APA (7th ed.) Citation

Rutledge, A. T., & Helgesen, J. O. (1991). A steady-state unsaturated-zone model to simulate pesticide transport. U.S. Geological Survey.

Chicago Style (17th ed.) Citation

Rutledge, A. T., and John O. Helgesen. A Steady-state Unsaturated-zone Model to Simulate Pesticide Transport. Lawrence, Kansas: U.S. Geological Survey, 1991.

MLA (9th ed.) Citation

Rutledge, A. T., and John O. Helgesen. A Steady-state Unsaturated-zone Model to Simulate Pesticide Transport. U.S. Geological Survey, 1991.