A book and a colloquium (March 11–14, 1981, Tucson, Arizona) on comets has been announced by the Organizing Committee, Lunar and Planetary Laboratory, University of Arizona. Little is known about comets, and thus books at almost any level on the subject are rare. Perhaps the most complete at this time is Comets, Asteroids, and Meteorites (A. H. Delsemme (Ed.), University of Toledo, Toledo, Ohio 1977), the published proceedings of the International Astronomical Union Colloquium in Grenoble, 1976. In light of the coming of Halley's comet in 1985 and the planned space missions to study comets in this decade, there is a great need for a more extensive source book on the subject, where none exists.