ISBN 0-8165-1148-9; also Sky Publishing Corporation, March 2006==External links==*Many biographical articles on Clyde Tombaugh*Quote from Tombaugh on UFOs*UFO activities of Tombaugh*Academic paper on Tombaugh's UFO activities and near-earth satellite search* Illinois proposes a Pluto Day and reinstate Pluto as a Planet in honor of C. Tombaugh: Illinois General Assembly, Senate Resolution SR0046 2/26/2009
ISBN 0-8165-1148-9; also Sky Publishing Corporation, March 2006==Liên kết ngoài==*Many biographical articles on Clyde Tombaugh*Quote from Tombaugh on UFOs*UFO activities of Tombaugh*Academic paper on Tombaugh's UFO activities and near-earth satellite search* Illinois proposes a Pluto Day and reinstate Pluto as a Planet in honor of C. Tombaugh: Illinois General Assembly, Senate Resolution SR0046 2/26/2009