APA (7th ed.) Citation

Geological Survey (U.S.). (1990). States of Maryland and Delaware [topographic]. The Survey.

Chicago Style (17th ed.) Citation

Geological Survey (U.S.). States of Maryland and Delaware [topographic]. Reston, Va.: The Survey, 1990.

MLA (9th ed.) Citation

Geological Survey (U.S.). States of Maryland and Delaware [topographic]. The Survey, 1990.

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