The study of the physics of cometary nuclei
Subtitle: semiannual progress reports no. 20 and 21 for the period 1 April 1984 through 31 March 1985
By: principal investigator, Fred L. Whipple.
Contributors: United States. National Aeronautics and Space Administration.
Series: NASA contractor report -- NASA CR-175917.
Publisher: Smithsonian Institution, Astrophysical Laboratory; National Technical Information Service, distributor
Published: 1985
Place of publication: Cambridge, Mass; [Springfield, Va
Language: eng
Format: Microform
Subjects: Comets.
Notes: Distributed to depository libraries in microfiche.

Microfiche. [Washington, D.C. : National Aeronautics and Space Administration, 1985] 1 microfiche.