Bascom, F.  1862-1945. <br/><br/>
The ancient volcanic rocks of South mountain, Pennsylvania / 
by Florence Bascom. 
 - Washington,  Govt. Print. Off.,  1896. 
 - 124 p. :  xxviii pl. (incl. maps) ;  24 cm. 
 - U.S. Geological survey. Bulletin  no. 136 .
 - United States.  Geological Survey.  Bulletin ;  136. .
<br/><br/> "Literature" : p. 87-91. 
<br/><br/>Bibliography : p. 19. 
<br/><br/><label>LCCN: </label>gs 05000702  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Petrology--Pennsylvania.<br/>Igneous rocks--Pennsylvania.
<br/><br/><label>LC Class. No.: </label>QE75  / .B9 no. 136