APA (7th ed.) Citation

Geological Survey (U.S.) & Drake, A. A. (1993). Bedrock geologic map of the Allentown West quadrangle, Lehigh and Berks counties, Pennsylvania. The Survey.

Chicago Style (17th ed.) Citation

Geological Survey (U.S.) and Avery Ala Drake. Bedrock Geologic Map of the Allentown West Quadrangle, Lehigh and Berks Counties, Pennsylvania. Reston, VA: The Survey, 1993.

MLA (9th ed.) Citation

Geological Survey (U.S.) and Avery Ala Drake. Bedrock Geologic Map of the Allentown West Quadrangle, Lehigh and Berks Counties, Pennsylvania. The Survey, 1993.