Swartz, Frank M.  1899- <br/><br/>
The Helderberg group from central Pennsylvania to southwestern Virginia, 
by Frank McKim Swartz ... 
 -  State College, Pa., School of mineral industries,  1929. 
 - 1 p. l., 14, [13] p.  incl. tables, diagrs.  23 cm. 
 - Bulletin (Pennsylvania State University. Mineral Industries Experiment Station) ;  no. 4 .
<br/><br/> [pt. 1] "reprinted from the Proceedings of the Pennsylvania academy of science, v. 3, 1929." 
<br/><br/>Contains references. 
<br/><br/><label>LCCN: </label>gs 31000159  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Paleontology--United States.<br/>Paleontology--Devonian.
<br/><br/><label>LC Class. No.: </label>QE728  / .S9