1999

Achenbach, Joel in his “Captured by Aliens” (1999) (available on Amazon USA and on Amazon UK) at pages 75-76, 78-89 (in Chapter 7), 91 (in Chapter 8), 103 (in Chapter 9), 144 (in Chapter 13), 361-362 (in Chapter 36), 379-380 (in the Notes) of the Simon and Schuster hardback edition.

21

1985

Angelo, Joseph A in his “The Extraterrestrial Encyclopedia: Man’s Search for Life in Outer Space” (1985) (available on Amazon USA and on Amazon UK) at pages 40, 41 (in the entry entitled “exobiology”), 91 (in the entry entitled “Mars”), 217-219 (in the entry entitled “Viking Project”) of the revised 1991 Fact on File hardback edition.

6

1989

Ashpole, Edward in his “The Search for Extraterrestrial Intelligence” (1989) (available on Amazon USA and on Amazon UK) at page 48 (in Chapter 3) of the Blandford softcover edition.

1

1997

Ashpole, Edward in his “Where is Everybody?” (1997) (available on Amazon USA and on Amazon UK) at pages 66-67 (in Chapter 5) of the Sigma Press softcover edition.

2

1979

Asimov, Isaac in his “Extraterrestrial Civilizations” (1979) (available on Amazon USA and on Amazon UK) at pages 57-60 (in Chapter 3) of the Crown hardback edition, at pages 71-74 of the Pan paperback edition.

4

1987

Baird, John C in his “The Inner Limits of Outer Space” (1987) (available on Amazon USA and on Amazon UK) at pages 98-99 (in Chapter 6) of the Dartmouth hardback edition.

2

1979

Ball, Brian in his “A Young Person’s Guide to UFOs” (1979) (available on Amazon USA and on Amazon UK) at page 56 (in Chapter 6) of the Dragon paperback edition.

1

2000

Bergreen, Laurence in his “The Quest For Mars” (2000) (available on Amazon USA and on Amazon UK) at pages 4, 14, 27 (in Chapter 1), 139 (in Chapter 6), 190-191, 192-203, 208, 216 (in Chapter 8) of the Harper hardback edition.

20

1997

Bizony, Piers in his “The Exploration of Mars: Searching for the Cosmic Origins of Life” (1997) (available on Amazon USA and on Amazon UK) at pages 27-62 (in Chapter 2 generally), 63-75 (in Chapter 3 generally), 148-149 (in Chapter 7) of the Aurum softcover edition.

51

1981

Bova, Ben in his “The High Road” (1981) (available on Amazon USA and on Amazon UK) at pages 231-233 (in Chapter 27) of the Houghton Mifflin hardback edition.

3

1979

Boyce, Chris in his Extraterrestrial Encounter (1979) (available on Amazon USA and on Amazon UK) at page 132 (in Chapter 9) of the David & Charles hardback edition, at page 121 of the 1980 revised NEL paperback edition.

1

1979

Brunstein, Karl in his “Beyond the Four Dimensions” (1979) (available on Amazon USA and on Amazon UK) at page 91 (in Chapter 5) of the Walker softcover edition.

1

1999

Chambers, Paul in his “Life On Mars” (1999) (available on Amazon USA and on Amazon UK) at pages 75-94 (in Chapter 7 generally), 95-98 (in Chapter 8), 104, 107, 109 (in Chapter 9), 177 (in Chapter 13­) of the Blandford hardback edition.

28

1999

Clark, Andrew J H and Clark, David H in their “Aliens“ (1999) (available on Amazon USA and on Amazon UK) at pages 2-3 (in the Prologue) of the Fromm hardback edition.

1

2000

Darling, David in his “The Extraterrestrial Encyclopedia” (2000) (available on Amazon USA and on Amazon UK) at pages 443-445 (in the entry entitled “Viking”), 445 (in the entry entitled “Viking gas chromatograph-mass spectrometer (GCMS)”), 445-446 (in the entry entitled “Viking gas exchange (GEX) experiment”), 446 (in the entry entitled “Viking labeled release (LR) experiment”), 446-447 (in the entry entitled “Viking pyrolytic release (PR) experiment”) of the Three Rivers softcover edition.

5

2003

Darling, David in his online encyclopedia, “The Encyclopedia of Astrobiology, Astronomy and Spaceflight” (2003) in the entries entitled “Viking”, “Viking gas chromatograph-mass spectrometer (GCMS)”, .” Viking gas exchange (GEX) experiment”, “Viking labeled release (LR) experiment”, “Viking pyrolytic release (PR) experiment” The relevant entries are available online, respectively at:

http://www.daviddarling.info/encyclopedia/V/Viking.html

http://www.daviddarling.info/encyclopedia/V/VikingGCMS.html

http://www.daviddarling.info/encyclopedia/V/VikingGEX.html http://www.daviddarling.info/encyclopedia/V/VikingLR.html http://www.daviddarling.info/encyclopedia/V/VikingPR.html

5

1999

Davidson, Keay in his “Carl Sagan: A Life” (1999) (available on Amazon USA and on Amazon UK) at pages 276-281 (in Chapter 10) of the Wiley softcover edition.

6

1995

Davies, Paul in his “Are we Alone?“ (1995) (available on Amazon USA and on Amazon UK) at page 9 (in Chapter 1) of the Penguin paperback edition.

1

1998

Davies, Paul in his “The Fifth Miracle” (1998) (available on Amazon USA and on Amazon UK) at page 152, 153-156, 165 (in Chapter 8) of the Penguin Press hardcover edition.

6

1998

Dick, Steven J in his “Life on Other Worlds“ (1998) (available on Amazon USA and on Amazon UK) at pages 58-65 (in Chapter 2) of the Cambridge hardback edition.

8

1996

Dick, Steven J in his “The Biological Universe” (1996) (available on Amazon USA and on Amazon UK) at pages 146-159 (in Chapter 3) of the Cambridge hardback edition.

14

1997

DiGregorio, Barry E in “Mars: The Living Planet” (1997) (by Barry E DiGregorio with Gilbert V Levin and Patricia Ann Straat) generally, particularly at pages xi-xiii (in the Preface), xv, xix (in the Acknowledgments), 10, 11-15, 16, 19 (in the Introduction), 22 (in Chapter 1), 52-53, 56, 68, 70, 71-72, 81 (in Chapter 2), 90-126 (in Chapter 3), 128-174 (in Chapter 4), 176-203 (in Chapter 5), 240-241, 252-253 (in Chapter 7) of the Frog hardback edition.

138

1975

Drake, W Raymond in his “Gods and Spacemen Throughout History” (1975) (available on Amazon USA and on Amazon UK) at page 19 (in Chapter 1) of the Sphere paperback edition.

1

1964

Drake, W Raymond in his “Messengers From the Stars” (1964) (Formerly “Gods or Spacemen?”) (available on Amazon USA and on Amazon UK) at pages 85-87 (in Chapter 5) of the Sphere paperback edition.

3

1978

Edelson, Edward in his “Who Goes There?” (1978) (available on Amazon USA and on Amazon UK) at pages xiii-xiv (in the Introduction), 1-17 (Chapter 1 generally) of the NEL paperback edition (with the same page numbering in the NEL paperback edition combining this book and Chris Boyce’s “Extraterrestrial Encounter).

25

1975

Fairley, Peter in his “Is there Life in Outer Space?” (1975) (available on Amazon USA and on Amazon UK) at pages 91-93 (in Chapter 6) of the Look-In softcover edition.

3

1980

Feinberg, Gerald and Shapiro, Robert in their “Life Beyond Earth” (1980) (available on Amazon USA and on Amazon UK) at pages 145 (in Chapter 6), 263-269, 274-305 (in Chapter 9), 417, 418, 421, 422, 423 (in Chapter 14) of the Morrow hardback edition.

45

1974

Flindt, Max H and Binder, Otto in their “Mankind – Child of the Stars” (1974) (available on Amazon USA and on Amazon UK) at pages 60-61 (in Chapter 3) of the Fawcett paperback edition.

2

1979

Fox, Phillis in “UFO Phenomena and the Behavioral Scientist” (1979) (edited by Richard F Haines) (available on Amazon USA and on Amazon UK) at page 24 (in Chapter 2) of the Scarebrow Press hardback edition.

1

1978

Friedman, Stanton T in “Worlds Beyond” (1978) (available on Amazon USA and on Amazon UK) (edited by Larry Geis and Fabrice Florin) at page 210 (in Sequence 21 entitled “Flying Saucers Are Real”) of the And/Or softcover edition (with the same page numbering in the Perennial Library paperback edition published under the title “Moving Into Space: The Myths and Realities of Extraterrestrial Life”).

1

1977

Gallant, Roy A in “Beyond Earth : The Search for Extraterrestrial Life” (1977) (available on Amazon USA and on Amazon UK) at pages 113-114 (in Chapter 9) of the Four Winds hardback edition.

2

1980

Goldsmith, Donald and Owen, Tobias in their “The Search for Life in the Universe” (1980) (available on Amazon USA and on Amazon UK) at pages 274-278, 284 (in Chapter 14), 289, 290-301, 302 of the Benjamin Cummings softcover edition, at pages 307-315, 320 (in Chapter 13), 327, 329-339, 346 (in Chapter 14) of the 1992 Addison Wesley softcover revised second edition.

20

1997

Goldsmith, Donald in his “The Hunt For Life On Mars” (1997) (available on Amazon USA and on Amazon UK) at pages 181-192 (in the unnumbered chapter entitled “Can Life Exist on Mars Now?”) of the Dutton hardback edition.

12

1976

Gribbin, John in his “Our Changing Universe” (1976) at page 115 (in Chapter 15) of the Futura paperback edition.

1

1997

Halpern, Paul in his “The Quest For Alien Planets” (1997) (available on Amazon USA and on Amazon UK) at pages 36-39 (in Chapter 1) of the Plenum Trade hardback edition.

4

1998

Hancock, Graham in his “The Mars Mystery” (1998) (available on Amazon USA and on Amazon UK) at pages 66-70 (in Chapter 7 generally) of the Crown hardback edition.

5

2000

Hansen, Terry in his “The Missing Times : News Media Complicity in the UFO Cover-Up : News Media Complicity in the UFO Cover -Up” (2000) (available on Amazon USA and on Amazon UK) at page 191 (in Chapter 5) of the Xlibris softcover edition.

1

1978

Haynes, Norman in “Worlds Beyond” (1978) (available on Amazon USA and on Amazon UK) (edited by Larry Geis and Fabrice Florin) at page 139 (in Sequence 15) of the And/Or softcover edition (with the same page numbering in the Perennial Library paperback edition published under the title “Moving Into Space: The Myths and Realities of Extraterrestrial Life”).

1

1995

Heidmann, Jean in his “Extraterrestrial Intelligence” (1995) (available on Amazon USA and on Amazon UK) at pages 79-80 (in Chapter 4) of the Cambridge hardback edition.

2

1995

Heidmann, Jean in his “Life in the Universe" (1995) (available on Amazon USA and on Amazon UK) at page 22 (in Chapter 1) of the Cambridge softcover edition.

1

1999

Hennessey, Roger in his “Worlds Without End : The Historic Search for Extraterrestrial Life” (1999) (available on Amazon USA and on Amazon UK) at page 121 (in Chapter 11) of the Tempus hardback edition.

1

1987

Hoagland, Richard in his “The Monuments of Mars” (1987) (available on Amazon USA and on Amazon UK) at page 4 (in Chapter 1) of the 1992 revised North Atlantic softcover edition.

1

1977

Horowitz, Norman H in “The Quest For Extraterrestrial Life : A Book of Readings” (1980) (edited by Donald Goldsmith) (available on Amazon USA and on Amazon UK) at pages 86-98 (in Chapter 19) of the University Science Books hardback edition. The relevant chapter is a reprint of “The Search For Life on Mars”, Scientific American, Volume 237 (1977.1100) pages 52-61.

13

1984

Hyams, Ron in “UFOs: Where Do They Come From?” (1984) (edited by Peter Brookesmith) (available on Amazon USA and on Amazon UK) at pages 76-77 (in the unnumbered chapter entitled “Reach for the stars”) of the Black Cat hardback edition. The relevant chapter is an article reprinted from the weekly partwork “The Unexplained” , Volume 1, pages 222-223.

2

1998

Jakosky, Bruce in his “The Search for Life on Other Planets” (1998) (available on Amazon USA and on Amazon UK) at pages 134-141 (in Chapter 8), 168 (in Chapter 10) of the Cambridge University softcover edition.

12

1989

Jastrow, Robert in his “Journey to the Stars: Space Exploration - Tomorrow and Beyond” (1989) (available on Amazon USA and on Amazon UK) at pages 137-140 (in Chapter 9) of the Bantam softcover edition.

4

2000

Koerner, David & LeVay, Simon in their “Here Be Dragons” (2000) (available on Amazon USA and on Amazon UK) at pages 64, 68-70 (in Chapter 3) of the Oxford softcover edition.

3

2001

Lamb, David in his “The Search for Extraterrestrial Intelligence : A Philosophical Inquiry” (2001) (available on Amazon USA and on Amazon UK) at pages 102-104 (in Chapter 4) of the Routledge softcover edition.

3

1976

Landsburg, Alan in his “In Search of Extraterrestrials” (1976) (available on Amazon USA and on Amazon UK) at pages 124 (in Chapter 10), 132, 136-143 (in Chapter 11) of the Corgi paperback edition.

10

1998

Lemonick, Michael in his “Other Worlds“ (1998) (available on Amazon USA and on Amazon UK) at page 197 (in Chapter 11) of the Simon & Schuster hardback edition (with the same page numbering in the Simon & Schuster softcover edition).

1

1997

Levin, Gilbert V in “Mars: The Living Planet” (1997) (by Barry E DiGregorio with Gilbert V Levin and Patricia Ann Straat) (available on Amazon USA and on Amazon UK) at pages 288-311 (in Chapter 9, by Gilbert V Levin) of the Frog hardback edition.

24

1977

Magor, John in his “Our UFO Visitors” (1977) (available on Amazon USA and on Amazon UK) at page 243-244 (in Chapter 12) of the Hancock House hardback edition.

2

1989

Mallove, Eugene F and Matloff, Gregory L in their “The Starflight Handbook” (1989) (available on Amazon USA and on Amazon UK) at pages 211-213 (in Chapter 15) of the Wiley hardback edition.

3

2001

McConnell, Brian in his “Beyond Contact : A Guide to SETI and Communicating with Alien Civilizations” (2001) (available on Amazon USA and on Amazon UK) at page 38 (in Chapter 4) of the O’Reilly hardback edition.

1

1999

McDonough, Thomas R in “Are We Alone in the Cosmos” (1999) (edited by Ben Bova and Byron Preiss) (available on Amazon USA and on Amazon UK) at page 87 (in Chapter 2) of the ibooks softcover edition.

1

1990

McDonough, Thomas R in “First Contact” (1990) (edited by Ben Bova and Byron Preiss) (available on Amazon USA and on Amazon UK) at page 68 (in Chapter 2) of the NAL Books hardback edition, at page 89 of the Headline paperback edition.

1

1987

McDonough, Thomas R in his “The Search for Extraterrestrial Intelligence - Listening for Life in the Cosmos” (1987) (available on Amazon USA and on Amazon UK) at pages 81-85 (in Chapter 6) of the Wiley softcover edition.

5

1987

Moore, Patrick and Jackson, Francis in their “Life in the Universe” (1987) (available on Amazon USA and on Amazon UK) at pages 91, 95-103 (in Chapter 5) of the Norton softcover edition.

`0

1998

Moore, Patrick in his “On Mars” (1998) (available on Amazon USA and on Amazon UK) at pages 134-147 (in Chapter 10 generally), 148, 149-155 (in Chapter 12) of the Seven Dials softcover edition.

22

2001

Morgan, Chris in his “Hardware : The Art of David A Hardy” (2001) at pages 26, 27 (in the unnumbered chapter entitled “A Life in Space Art”) of the Paper Tiger hardback edition.

2

1990

Morrison, Philip in an interview in David W Swift’s “SETI Pioneers : Scientists Talk About Their Search for Extraterrestrial Intelligence” (1990) (available on Amazon USA and on Amazon UK) at page 36 (in the unnumbered chapter entitled “Philip Morrison”) of the Arizona hardback edition.

1

1999

Papagiannis, Michael in “Are We Alone in the Cosmos” (1999) (edited by Ben Bova and Byron Preiss) (available on Amazon USA and on Amazon UK) at page 206 (in Chapter 5) of the ibooks softcover edition.

1

1990

Papagiannis, Michael in “First Contact” (1990) (edited by Ben Bova and Byron Preiss) (available on Amazon USA and on Amazon UK) at page 182 (in Chapter 5) of the NAL Books hardback edition, at page 233 of the Headline paperback edition.

1

1998

Parker, Barry in his “Alien Life” (1998) (available on Amazon USA and on Amazon UK) at pages 73-76, 83-85 (in Chapter 5) of the Plenum Trade hardback edition.

7

2003

Pillinger, Colin in his “Beagle” (2003) (available on Amazon USA and on Amazon UK) at page 155 (in the unnumbered chapter entitled “Tales of Two Beagles”) of the Faber and Faber hardback edition.

1

1996

Pope, Nick in his “Open Skies, Closed Minds” (1996) (available on Amazon USA and on Amazon UK) at page 205 (in Chapter 12) of the Simon and Schuster hardback edition, with the same page numbering in the Pocket Books paperback edition.

1

1999

Poundstone, William in his “Carl Sagan: A Life in the Cosmos” (1999) (available on Amazon USA and on Amazon UK) at pages xvi (in the Foreword), 136-137, 163-168, 179-185, 193-194 (in the chapter entitled “Ithaca 1968-76”), 199-223 (in the chapter entitled “Pasadena 1976”), 224-230 (in the chapter entitled “Ithaca 1977-78”) of the Owl Books softcover edition.

50

1977

Pournelle, Jerry in “Closeup: New Worlds” (1977) (edited by Bova, Ben with Bell, Trudy) at pages 62, 70-77 (in the unnumbered chapter entitled “The Old and New Mars”) of the St Martin’s Press hardback edition.

9

1991

Randles, Jenny and Hough, Peter in their “Looking for the Aliens” (1991) (available on Amazon USA and on Amazon UK) at page 76 (in Chapter 9) of the Blandford softcover edition.

1

1985

Regis, Edward in “Extraterrestrials: Science and alien intelligence” (1985) (edited by Edward Regis) (available on Amazon USA and on Amazon UK) at pages 234-235 (in Part 6) of the Cambridge University Press softcover edition.

2

1983

Ridpath, Ian in his “Life Off Earth” (1983) (available on Amazon USA and on Amazon UK) at pages 83-84, 85 (in Chapter 7) of the Granada hardback edition.

3

1978

Ridpath, Ian in his “Messages from the Stars” (1978) (available on Amazon USA and on Amazon UK) at pages 11 (in Chapter 1), 64-79 (Chapter 4 generally) of the Fontana paperback edition.

17

1975

Ridpath, Ian in his “Worlds Beyond” (1975) (available on Amazon USA and on Amazon UK) at pages 113-116 (in Chapter 6) of the Wildwood House softcover edition, at pages 115-121 of the revised 1977 Penguin softcover edition entitled “Signs of Life”.

4

1987

Ross, Daniel in his “UFOs and the Complete Evidence from Space: The Truth About Venus, Mars and the Moon” (1987) (available on Amazon USA and on Amazon UK) at pages 83-92 (in Chapter 5) of the Pintado softcover edition.

10

1973

Roulet, Alfred in his “The Search for Intelligent Life in Outer Space” (1973) (available on Amazon USA and on Amazon UK) at pages 109-110 (in the unnumbered chapter entitled “The Odds on Life in Space”) of the Berkley paperback edition.

2

1977

Sachs, Margaret and Jahn, Ernest in their “Celestial Passengers – UFOs & Space Travel” (1977) (available on Amazon USA and on Amazon UK) at pages 64, 66-67 (in Chapter 7) of the Penguin paperback edition.

3

1998

Sagan, Carl in his “Billions and Billions” (1998) (available on Amazon USA and on Amazon UK) at page 52 (in Chapter 5) of the Headline softcover edition.

1

1979

Sagan, Carl in his “Broca’s Brain” (1979) (available on Amazon USA and on Amazon UK) at page 226 (in Chapter 12) of the Coronet paperback edition.

1

1980

Sagan, Carl in his “Cosmos“ (1980) (available on Amazon USA and on Amazon UK) at pages 137-153 (in Chapter 5) of the Abacus softcover edition.

17

1975

Sagan, Carl in his “Other Worlds“ (1975) (available on Amazon USA and on Amazon UK) at pages 92-93 of the Bantam paperback edition.

2

1994

Sagan, Carl in his “Pale Blue Dot” (1994) (available on Amazon USA and on Amazon UK) at pages 223 (in Chapter 14), 237, 239-243 (in Chapter 15) of the Random House softcover edition.

7

1997

Sagan, Carl in his “The Demon Haunted World” (1997) (available on Amazon USA and on Amazon UK) at pages 105-106 (in Chapter 6) of the Headline softcover edition.

2

1999

Shapiro, Robert in his “Planetary Dreams” (1999) (available on Amazon USA and on Amazon UK) at pages 189-191, 197, 207-211 (in Chapter 9) of the Wiley hardback edition.

9

1998

Shostak, Seth in his “Sharing the Universe” (1998) (available on Amazon USA and on Amazon UK) at pages 27-30 (in Chapter 2) of the Berkeley Hills softcover edition.

4

1997

Spencer, John and Spencer, Anne in their “True Life Encounters – Alien Contact” (1997) (available on Amazon USA and on Amazon UK) at pages 25-26 (in Chapter 2) of the Millenium paperback edition.

2

1974

Spencer, John Wallace in his “No Earthly Explanation” (1974) (available on Amazon USA and on Amazon UK) at pages 162-163 (in Chapter 8) of the Corgi paperback edition.

2

1978

Stemman, Roy in his “Mysteries of the Universe: Great Mysteries” (1978) (available on Amazon USA and on Amazon UK) at pages 105-106, 107 (in Chapter 4) of the Book Club Associates hardback edition.

3

1977

Stilley, Frank in his “The Search” (1977) (available on Amazon USA and on Amazon UK) at page 39 (in Chapter 3) of the Putnam hardback edition.

1

1976

Stoneley, Jack and Lawton, A T in their “CETI: Communication with Extra-Terrestrial Intelligence” (1976) (available on Amazon USA and on Amazon UK) at pages 135-138 (in Chapter 17 generally) of the Star Books paperback edition.

4

1974

Stoneley, Jack and Lawton, A T in their “Is Anyone Out There?” (1974) (available on Amazon USA and on Amazon UK) at pages 224-228 (in Chapter 13) of the Star Books paperback edition.

5

1997

Straat, Patricia Ann in “Mars: The Living Planet” (1997) (by Barry E DiGregorio with Gilbert V Levin and Patricia Ann Straat) (available on Amazon USA and on Amazon UK) at pages 314-318 (in the Closing Comments, by Patricia Ann Straat) of the Frog hardback edition.

5

2004

Tonnies, Mac in his “After the Martian Apocalypse” (2004) (available on Amazon USA and on Amazon UK) at pages 39 (in Chapter 2), 267 (in Chapter 12) of the Paraview Pocket Books softcover edition.

2

2000

Ward, Peter and Brownlee, Don in their “Rare Earth” (2000) (available on Amazon USA and on Amazon UK) at pages xx-xxi (in the Introduction), 252-255 (in Chapter 11) of the Copernicus softcover edition.

6

1977

Washburn, Mark in his “Mars at Last!” (1977) (available on Amazon USA and on Amazon UK) at pages 1-3, 4-5, 6 (in Chapter 1), 55-56 (in Chapter 4), 59 (in Chapter 5), 91, 107 (in Chapter 8), 108 (in Chapter 9), 120-150 (in Chapter 10 generally), 151-170 (in Chapter 11 generally), 171-193 (in Chapter 12 generally), 194-206 (in Chapter 13 generally), 207-221 (in Chapter 14 generally) of the Abacus paperback edition.

114

1975

Weldon, John and Levitt, Zola in their “Encounters With UFOs“ (1975) (formerly “UFOs, What on Earth is Happening?”) (available on Amazon USA and on Amazon UK) at page 11 (in Chapter 1) of the Harvest House paperback edition.

1

1999

White, Michael in his “Alien Life Forms : Sci-Fi Explained” (1999) (available on Amazon USA and on Amazon UK) at pages 19-20 (in Chapter 1) of the Penguin paperback edition.

2

1998

White, Michael in his “Life Out There” (1998) (available on Amazon USA and on Amazon UK) at pages 6 (in Chapter 1), 124-[insert check White] (in Chapter 7) of the Little, Brown & Co hardback edition.

1997

Wilkinson, David in his “Alone in the Universe?” (1997) (available on Amazon USA and on Amazon UK) at page 32 (in Chapter 2) of the Monarch softcover edition.

1

1999

Zubrin, Robert in his “Entering Space: Creating a Spacefaring Civilization” (1999) (available on Amazon USA and on Amazon UK) at page 111 (in Chapter 6) of the Tarcher Putnam hardback edition.

1

1996

Zubrin, Robert in his “The Case for Mars” (1996) (available on Amazon USA and on Amazon UK) at pages 19-20, 27, 30-36 (in Chapter 2) of the Simon & Schuster softcover edition.

9