Encyclopaedia Britannica <br/><br/>
Encyclopaedia Britannica: Year Of Science And Future 

 - Chicago  William Benton  1972 
 - 448p. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Av1n
<br/><br/><label>Dewey Class. No.: </label>Av1n  / K2