APA (7th ed.) Citation

Project Gutenberg, Beard, C. A., & Beard, M. R. (2005). History of the United States. Project Gutenberg Literary Archive Foundation.

Chicago Style (17th ed.) Citation

Project Gutenberg, Charles A. Beard, and Mary Ritter Beard. History of the United States. Salt Lake City: Project Gutenberg Literary Archive Foundation, 2005.

MLA (9th ed.) Citation

Project Gutenberg, et al. History of the United States. Project Gutenberg Literary Archive Foundation, 2005.

Warning: These citations may not always be 100% accurate.