APA (7th ed.) Citation

Smith, R. C. (1977). Zinc and lead occurrences in Pennsylvania. Pennsylvania Geological Survey.

Chicago Style (17th ed.) Citation

Smith, Robert Charles. Zinc and Lead Occurrences in Pennsylvania. Harrisburg: Pennsylvania Geological Survey, 1977.

MLA (9th ed.) Citation

Smith, Robert Charles. Zinc and Lead Occurrences in Pennsylvania. Pennsylvania Geological Survey, 1977.