APA (7th ed.) Citation

(1980). Metric topographic map of Indiana Dunes National Lakeshore: 41086-E7-PM-050 (Rev. from aerial photographs taken 1977. Field checked 1979.). U.S. Geological Survey.

Chicago Style (17th ed.) Citation

Metric Topographic Map of Indiana Dunes National Lakeshore: 41086-E7-PM-050. Rev. from aerial photographs taken 1977. Field checked 1979. Reston, VA: U.S. Geological Survey, 1980.

MLA (9th ed.) Citation

Metric Topographic Map of Indiana Dunes National Lakeshore: 41086-E7-PM-050. Rev. from aerial photographs taken 1977. Field checked 1979. U.S. Geological Survey, 1980.