APA (7th ed.) Citation

Bradbury, J. C. (1956). Geologic structure map of the northwestern Illinois zinc-lead district. [publisher not identified].

Chicago Style (17th ed.) Citation

Bradbury, James C. Geologic Structure Map of the Northwestern Illinois Zinc-lead District. Urbana: [publisher not identified], 1956.

MLA (9th ed.) Citation

Bradbury, James C. Geologic Structure Map of the Northwestern Illinois Zinc-lead District. [publisher not identified], 1956.