APA (7th ed.) Citation

Maryland Geological Survey, Swartz, C. K., Prouty, W. F., Ulrich, E. O., & Bassler, R. S. (1923). Silurian. The Johns Hopkins press.

Chicago Style (17th ed.) Citation

Maryland Geological Survey, Charles Kephard Swartz, William F. Prouty, Edward Oscar Ulrich, and Ray S. Bassler. Silurian. Baltimore: The Johns Hopkins press, 1923.

MLA (8th ed.) Citation

Maryland Geological Survey, et al. Silurian. The Johns Hopkins press, 1923.