Donn, B. <br/><br/>
The study of comets  pt. 2 
B. Donn.. [et al.]                                                     
 - Washington  National Aeronautics and Space Administration  1976 
 - [various pagings.] 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Astronomy and astrophysics thesaurus<br/>Comets<br/>Periodic comets<br/>Solar system
<br/><br/><label>Universal Decimal Class. No.: </label>082.2:52  / IAU-C25.2