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Bova, Ben "Martians," Ad Astra (September/October 1992) 43-47

Burland, C.A. Myths of Life and Death (Crown Publishers, 1974)

Flaum, Eric The Planets (Michael Friedman Publishing Group, Inc., 1988)

Hoyle, Fred Astronomy and Cosmology (W. H. Freeman and Company, 1975)

Hoyt, William Graves Lowell and Mars (The University of Arizona Press, 1976)

Hoyt, William Graves Planet X and Pluto (The University of Arizona Press, 1980)

Jastrow, Robert and Malcolm H. Thompson Astronomy: Fundamentals and Frontiers (John Wiley & Sons, Inc., 1972, 1974)

Koss, John "Planet X," Ad Astra (September/October, 1993) 47-48

Littmann, Mark Planets Beyond (John Wiley & Sons, Inc., 1990)

Mitton, Simon, ed. The Cambridge Encylcopaedia of Astronomy (Trewin Copplestone Publishing Ltd, 1977)

Moore, Patrick Guide To Mars (Lutterworth Press, 1977)

Nicholson, Iain The Illustrated World of Space (Simon & Schuster, 1991)

Tombaugh, Clyde W. and Patrick Moore Out of the Darkness (Stackpole Books,1980)

Wagner, Richard "Nein on Nine?," Ad Astra (September/October, 1993) 39-41

Westfall, Richard S. The Life of Isaac Newton (Cambridge University Press, 1993)

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