APA (7th ed.) Citation

Geological Survey (U.S.), O'Sullivan, R. B., & Hail, W. J., Jr. (1987). Preliminary geologic map of the Forked Gulch quadrangle, Garfield County, Colorado. The Survey.

Chicago Style (17th ed.) Citation

Geological Survey (U.S.), Robert Brett O'Sullivan, and William J. Hail, Jr. Preliminary Geologic Map of the Forked Gulch Quadrangle, Garfield County, Colorado. Reston, Va.: The Survey, 1987.

MLA (9th ed.) Citation

Geological Survey (U.S.), et al. Preliminary Geologic Map of the Forked Gulch Quadrangle, Garfield County, Colorado. The Survey, 1987.