International geological Congress :  report of the twenty-third session Czechoslovakia 1968. Abstracts. / 
edited by Jan Petranek 
 - New Delhi :  Academia,  1964 
 - 396 p. ;  24 cm. 
<br/><br/> English, French, or German 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geology--Congresses<br/>Physical geology--Congresses
<br/><br/><label>Dewey Class. No.: </label>550.63