APA (7th ed.) Citation

Geological Survey (U.S.). National Mapping Division & Geological Survey (U.S.). National Mapping Division. (1993). Maryland, Delaware, and District of Columbia: Index to topographic and other map coverage. The Survey.

Chicago Style (17th ed.) Citation

Geological Survey (U.S.). National Mapping Division and Geological Survey (U.S.). National Mapping Division. Maryland, Delaware, and District of Columbia: Index to Topographic and Other Map Coverage. Reston, Va.: The Survey, 1993.

MLA (9th ed.) Citation

Geological Survey (U.S.). National Mapping Division and Geological Survey (U.S.). National Mapping Division. Maryland, Delaware, and District of Columbia: Index to Topographic and Other Map Coverage. The Survey, 1993.