APA (7th ed.) Citation

Geological Survey (U.S.) & ProQuest (Firm). Department of the Interior. United States Geological Survey. Charles D. Walcott, Director. Economic geology of the Beaver Quadrangle, Pennsylvania (southern Beaver and northwestern Allegheny counties). [publisher not identified].

Chicago Style (17th ed.) Citation

Geological Survey (U.S.) and ProQuest (Firm). Department of the Interior. United States Geological Survey. Charles D. Walcott, Director. Economic Geology of the Beaver Quadrangle, Pennsylvania (southern Beaver and Northwestern Allegheny Counties). Washington: [publisher not identified].

MLA (9th ed.) Citation

Geological Survey (U.S.) and ProQuest (Firm). Department of the Interior. United States Geological Survey. Charles D. Walcott, Director. Economic Geology of the Beaver Quadrangle, Pennsylvania (southern Beaver and Northwestern Allegheny Counties). [publisher not identified].