William D. Sevon
Appalachian geomorphology
Geology and mineral resources of Pike County, Pennsylvania. by W.D. Sevon [and others]
Geology and mineral resources of the Skytop quadrangle, Monroe and Pike Counties, Pennsylvania
Geology and mineral resources of the Skytop quadrangle, Monroe and Pike counties, Pennsylvania / by W.D. Sevon and Thomas M. Berg, Pennsylvania Geological Survey
Pennsylvania and the ice age