APA (7th ed.) Citation

Geological Survey (U.S.). (1976). National topographic maps 1: 250,000-scale series. Geological Survey.

Chicago Style (17th ed.) Citation

Geological Survey (U.S.). National Topographic Maps 1: 250,000-scale Series. Reston, Va.: Geological Survey, 1976.

MLA (9th ed.) Citation

Geological Survey (U.S.). National Topographic Maps 1: 250,000-scale Series. Geological Survey, 1976.