The geology of mineral deposits in south-central Pennsylvania : October 4th and 5th, 1968 : Pennsylvania Geological Survey, Harrisburg, Pennsylvania /

Harrisburg, Pa. : Bureau of Topographic and Geologic Survey, 1968

Energy & environments : geology in the "nether world" of Indiana County, Pennsylvania : October 6th-8th 2016 /

[Harrisburg, PA] : [Field Conference of Pennsylvania Geologists], 2016

Oil and gas in Pennsylvania /

by Flaherty, Kathy J.
Harrisburg, Pa. : Commonwealth of Pennsylvania, Dept. of Conservation and Natural Resources, Bureau of Topographic and Geologic Survey, 2002
2nd ed.