APA (7th ed.) Citation

Smith, W. H., Reinertsen, D. L., & Searight, T. K. (1957). Strippable coal reserves of Illinois. [publisher not identified].

Chicago Style (17th ed.) Citation

Smith, William Henking, David L. Reinertsen, and T. K. Searight. Strippable Coal Reserves of Illinois. Urbana: [publisher not identified], 1957.

MLA (9th ed.) Citation

Smith, William Henking, et al. Strippable Coal Reserves of Illinois. [publisher not identified], 1957.