Sources Falk, Dan, "More than a one-hit wonder", Astronomy, February 2006, 40–45. David H. Levy Clyde Tombaugh: Discoverer of the Planet Pluto (Tucson, Ariz.: University of Arizona Press, 1991). ; also Sky Publishing Corporation, March 2006.
Sources Falk Dan, "More than a one-hit wonder", Astronomy, February 2006, 40–45. David H. Le,vy Clyde Tombaugh: Discoverer of the Planet Pluto (Tucson, Ariz.: University of Arizona Press, 1991). ; also Sky Publishing Corporation, March 2006.