Britannica book of the year 1961 
edited by John Armitage                                         
 - Chicago  Encyclopaedia Britannica  1961 
 - 564p 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Astronomy and Astrophysics Thesaurus<br/>Yearbook
<br/><br/><label>Universal Decimal Class. No.: </label>31  / ARM