Ward, L. W., & Blackwelder, B. W. (1980). Stratigraphic revision of upper Miocene and lower Pliocene beds of the Chesapeake group, middle Atlantic Coastal Plain. United States Department of the Interior, Geological Survey.
Chicago Style (17th ed.) CitationWard, Lauck W., and Blake W. Blackwelder. Stratigraphic Revision of Upper Miocene and Lower Pliocene Beds of the Chesapeake Group, Middle Atlantic Coastal Plain. [Reston, Va.]: United States Department of the Interior, Geological Survey, 1980.
MLA (9th ed.) CitationWard, Lauck W., and Blake W. Blackwelder. Stratigraphic Revision of Upper Miocene and Lower Pliocene Beds of the Chesapeake Group, Middle Atlantic Coastal Plain. United States Department of the Interior, Geological Survey, 1980.
Warning: These citations may not always be 100% accurate.