Mineral collecting in Pennsylvania /

by Geyer, Alan R., Smith, Robert Charles, 1945-, Barnes, John Henry, 1946-
Harrisburg, Pa. : Commonwealth of Pennsylvania, Dept. of Environmental Resources, Topographic and Geologic Survey : May be purchased from State Book Store, 1976
4th ed.

Stratigraphic correlation chart of Pennsylvania /

Harrisburg, Pa. : Commonwealth of Pennsylvania, Dept. of Environmental Resources, Topographic and Geologic Survey : May be purchased from State Book Store, 1983

Stratigraphic correlation chart of Pennsylvania /

[Harrisburg] : Commonwealth of Pennsylvania, Dept. of Environmental Resources, Bureau of Topographic and Geologic Survey, 1993
3rd print., slightly rev. 1993.

Fossil collecting in Pennsylvania /

by Hoskins, Donald M.
Harrisburg : Commonwealth of Pennsylvania, Dept. of Environmental Resources, Office of Resources Management, Bureau of Topographic and Geologic Survey : Copies purchased from State Book Store, 1983
Third edition.