APA (7th ed.) Citation

Southwick, D. L., Edwards, J., & Owens, J. P. (1969). The geology of Harford County, Maryland. Maryland Geological Survey.

Chicago Style (17th ed.) Citation

Southwick, D. L., Jonathan Edwards, and James Patrick Owens. The Geology of Harford County, Maryland. Baltimore: Maryland Geological Survey, 1969.

MLA (8th ed.) Citation

Southwick, D. L., et al. The Geology of Harford County, Maryland. Maryland Geological Survey, 1969.