APA (7th ed.) Citation

Leighton, M. M., & Folk, S. H. (1944). Undiscovered oil reserves in Illinois. [publisher not identified].

Chicago Style (17th ed.) Citation

Leighton, Morris M., and Stewart Huntley Folk. Undiscovered Oil Reserves in Illinois. Urbana, Ill.: [publisher not identified], 1944.

MLA (9th ed.) Citation

Leighton, Morris M., and Stewart Huntley Folk. Undiscovered Oil Reserves in Illinois. [publisher not identified], 1944.