"Poor's Manual of Railroads". H.V. & H.W. Poor. September 29, 1891. Archived from the original on August 4, 2024. Retrieved October 1, 2021 – via Google Books.
Lapham, I. A. On the Man-shaped Mounds of Wisconsin.Report and Collections of the State Historical Society of Wisconsin for the years 1857 and 1858, v. 4, 1859, pp. 365–368. (copy)
Lapham, I. A. Geologic map of Wisconsin 1869Archived August 4, 2024, at the Wayback Machine. UWM Libraries Digital Collections, American Geographical Society Library Digital Map Collection. Accessed April 24, 2011.
"Poor's Manual of Railroads". H.V. & H.W. Poor. September 29, 1891. Archived from the original on August 4, 2024. Retrieved October 1, 2021 – via Google Books.
Lapham, I. A. Geologic map of Wisconsin 1869Archived August 4, 2024, at the Wayback Machine. UWM Libraries Digital Collections, American Geographical Society Library Digital Map Collection. Accessed April 24, 2011.