Oil and gas developments in Pennsylvania in 1979 / compiled by Robert G. Piotrowski.Robert G. Piotrowski · First published 1980Open the Tome
Oil and gas developments in Pennsylvania in 1978 / by Robert G. Piotrowski ... [et al.].Robert G. Piotrowski · First published 1979Open the Tome
Oil & Gas Developments in Pennsylvania in 1978 (Progress Report (Pennsylvania. Bureau of Topographic and Geo)Robert G. Piotrowski · First published 1984Open the Tome
Geology and natural gas production of the Lower Silurian Medina group and equivalent rock units in PennsylvaniaRobert G. Piotrowski · First published 1981Open the Tome
Black shale and sandstone facies of the Devonian "Catskill" clastic wedge in the subsurface of western PennsylvaniaRobert G. Piotrowski · First published 1979Open the Tome
