lower left on stone: Pennell; lower left verso in graphite by unknown hand: The Big Mill, Gary, Indiana 1915 / W. 405
- Wuerth, Louis A. Catalogue of the Lithographs of Joseph Pennell. Boston: Little, Brown and Co., 1931, p. 148, no. 405.
- Beall, Karen F. and David W. Kiehl. Graphic Excusrions: American Prints in Black and White, 1900-1950, Selections from the Collection of Reba and Dave Williams. David R. Godine, Boston; American Federation of Arts, New York, 1991: 4