Kosanke, Robert M. <br/><br/>
Palynological studies of Middle Pennsylvania coal beds of the proposed Pennsyvania System stratotype in West Virginia / 
by Robert M. Kosanke 
 - Washington D. C. :  U. S. Government Printing Office,  1988. 
 - vi, 73 p. :  ill ;  27 cm 
 - U. S. Geological Survey professional paper ;  1455 .