APA (7th ed.) Citation

Geological Survey (U.S.) & Ryder, R. T. (1991). Stratigraphic framework of Cambrian and Ordovician rocks in the central Appalachian Basin from Richland County, Ohio to Rockingham County, Virginia. U.S. Geological Survey ; For sale by U.S. Geological Survey, Map Distribution.

Chicago Style (17th ed.) Citation

Geological Survey (U.S.) and Robert T. Ryder. Stratigraphic Framework of Cambrian and Ordovician Rocks in the Central Appalachian Basin from Richland County, Ohio to Rockingham County, Virginia. Reston, Va. : Denver, CO: U.S. Geological Survey ; For sale by U.S. Geological Survey, Map Distribution, 1991.

MLA (9th ed.) Citation

Geological Survey (U.S.) and Robert T. Ryder. Stratigraphic Framework of Cambrian and Ordovician Rocks in the Central Appalachian Basin from Richland County, Ohio to Rockingham County, Virginia. U.S. Geological Survey ; For sale by U.S. Geological Survey, Map Distribution, 1991.