Gehlen, K. von <br/><br/>
The environmental impacts of exploitation of oil shales  and tar sands / 
K.Von Gehlen 
 - Nairobi:  United Naions Environment Programme,  1985 
 - 148p.:  ill. 
 - Energy report series;  ERS-13-85 .
<br/><br/> At head of title: Institute of Geochemistry, Petrology and Economic Geology, University of Frankfurt am Main 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Oil-shale industry--Environmental aspects<br/>Oil sands--Environmental aspects