APA (7th ed.) Citation

United States. Bureau of Agricultural Economics, United States. Bureau of the Census, & Geological Survey. (1935). [Outline map of the United States, showing county boundaries]. Bureau of Agricultural Economics.

Chicago Style (17th ed.) Citation

United States. Bureau of Agricultural Economics, United States. Bureau of the Census, and Geological Survey. [Outline Map of the United States, Showing County Boundaries]. [Washington, D.C.]: Bureau of Agricultural Economics, 1935.

MLA (8th ed.) Citation

United States. Bureau of Agricultural Economics, et al. [Outline Map of the United States, Showing County Boundaries]. Bureau of Agricultural Economics, 1935.