Grim, Ralph E.  1902- <br/><br/>
Petrographic and ceramic properties of Pennsylvanian shales of Illinois, 
by Ralph E. Grim. Printed by authority of the state of Illinois. 
 - Urbana, Illinois,  1941. 
 - 15 p.  illus. 
<br/><br/> At head of title: State of Illinois. Department of Registration and Education. Division of the State Geological Survey.  "Reprinted from the Journal of the American Ceramic Society, vol. 24, no. 1, pp. 23-28, 1941." 
<br/><br/>Bibliographical foot-notes. 
<br/><br/><label>LCCN: </label>gs 41000049  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Shale.
<br/><br/><label>LC Class. No.: </label>QE471  / .G74