APA (7th ed.) Citation

Pennsylvania. Bureau of Topographic and Geologic Survey & Gray, C. (1960). Geologic map of Pennsylvania: Pennsylvania Geologic Survey, 4th ser. [publisher not identified].

Chicago Style (17th ed.) Citation

Pennsylvania. Bureau of Topographic and Geologic Survey and Carlyle Gray. Geologic Map of Pennsylvania: Pennsylvania Geologic Survey, 4th Ser. [Harrisburg]: [publisher not identified], 1960.

MLA (9th ed.) Citation

Pennsylvania. Bureau of Topographic and Geologic Survey and Carlyle Gray. Geologic Map of Pennsylvania: Pennsylvania Geologic Survey, 4th Ser. [publisher not identified], 1960.

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