Grim, Ralph E.  1902- <br/><br/>
Petrology of the Pennsylvania underclays of Illinois, 
by Ralph E. Grim and Victor T. Allen. 
 - Urbana, Ill.,  Printed by authority of the state of Illinois,  1938. 
 - 1485-1514p.  illus(map)2pl. on ll.,tables(part fold.)  25cm. 
 - Illinois.  State geological survey.  Report of investigations  no. 52 .
<br/><br/> cover title.  At head of title: State of Illinois ... Department of registration and education ... Division of the State geological survey ...  Reprinted from the Bulletin, Geological Society of America, vol. 49, 1938. 
<br/><br/>"Works to which reference is made": p. 1500-1510. 
<br/><br/><label>LCCN: </label>gs 39000002  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Petrology--Illinois.<br/>Clay--Illinois.
<br/><br/><label>LC Class. No.: </label>QE105  / .A25 no. 52