Crook, A. R.  1864- <br/><br/>
Geology of Sangamon County, 
by A. R. Crook ... 1912. 
 - Springfield, Ill.,  Illinois State journal co., state printers,  1912. 
 - 24 p.  illus.  23 cm. 
<br/><br/> "Literature on Sangamon County geology": p. 24. 
<br/><br/><label>LCCN: </label>gs 13000026  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geology--Illinois--Sangamon County.
<br/><br/><label>LC Class. No.: </label>QE106.S3  / C8