Condra, Geo. E.  1869-1958. <br/><br/>
The Grenola formation, 
by G. E. Condra and C. E. Busby. 
 - [Lincoln]  Printed by the authority of the state of Nebraska,   1933. 
 - 31 p.  illus. 
<br/><br/>Bibliographical foot-notes. 
<br/><br/><label>LCCN: </label>gs 34000052  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geology--Nebraska.
<br/><br/><label>LC Class. No.: </label>QE135  / .A43 no. 1