International petroleum encyclopedia. 

 - Tulsa, Oklahoma :  PennWell,  c1991 -    . 
 - vols.  ill. (part col.), col. maps. 
<br/><br/><label>ISBN: </label>0878143769 
<br/><br/><label>LCCN: </label>93014275 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Petroleum industry and trade--Periodicals.<br/>Petroleum industry and trade--Directories.