MULLENS, Marjorie C. <br/><br/>
Selected Annotated Bibliography on asphalt-Bearing Rocks of the United States and Canada to 1970 / 
By Marjorie C. Mullens and Albert E. Roberts. 
 -- Washington :   United states Government Printing Office,   1972 
 - 218 p. -- 
 (Geological Survey Bulletin  ; 1352).
<br/><br/> Fecha real de registro 12-03-1973 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Asfalto<br/>Canada<br/>Estados Unidos
<br/><br/><label>Universal Decimal Class. No.: </label>553.985(71+73)(01)