APA (7th ed.) Citation

Geological Survey (U.S.), Arkansas Geological Survey, & Pratt, W. P. (1992). Maps showing areal extent of selected Paleozoic shales in the northern midcontinent, U.S.A. The Survey.

Chicago Style (17th ed.) Citation

Geological Survey (U.S.), Arkansas Geological Survey, and Walden P. Pratt. Maps Showing Areal Extent of Selected Paleozoic Shales in the Northern Midcontinent, U.S.A. Reston, Va.: The Survey, 1992.

MLA (9th ed.) Citation

Geological Survey (U.S.), et al. Maps Showing Areal Extent of Selected Paleozoic Shales in the Northern Midcontinent, U.S.A. The Survey, 1992.