APA Citation

Estados Unidos. Geological Survey. (1971). Index to national topographic maps. Washington: The Survey.

Chicago Style Citation

Estados Unidos. Geological Survey. Index to National Topographic Maps. Washington: The Survey, 1971.

MLA Citation

Estados Unidos. Geological Survey. Index to National Topographic Maps. Washington: The Survey, 1971.

Warning: These citations may not always be 100% accurate.