APA (7th ed.) Citation

Geological Survey (U.S.) & Geological Survey (U.S.). National Mapping Division. (1989). Index to USGS/DMA 1: 50,000-scale, 15-minute mapping (contours and elevations in meters). The Survey.

Chicago Style (17th ed.) Citation

Geological Survey (U.S.) and Geological Survey (U.S.). National Mapping Division. Index to USGS/DMA 1: 50,000-scale, 15-minute Mapping (contours and Elevations in Meters). Reston, Va.: The Survey, 1989.

MLA (9th ed.) Citation

Geological Survey (U.S.) and Geological Survey (U.S.). National Mapping Division. Index to USGS/DMA 1: 50,000-scale, 15-minute Mapping (contours and Elevations in Meters). The Survey, 1989.