Oil and gas developments in Pennsylvania in 1953 /

by Fettke, Charles R. (Charles Reinhard), 1888-1959
[Harrisburg, Pa.] : Pennsylvania, Bureau of Topographic and Geologic Survey, 1954

Oil and gas developments in Pennsylvania in 1958 /

by Lytle, William S.
[Harrisburg, Pa.] : Commonwealth of Pennsylvania, Dept. of Internal Affairs, Topographic and Geologic Survey, 1959