APA (7th ed.) Citation

Rothrock, E. P. (1931). A preliminary report on the chalk of eastern South Dakota. [publisher not identified].

Chicago Style (17th ed.) Citation

Rothrock, E. P. A Preliminary Report on the Chalk of Eastern South Dakota. Vermillion, South Dakota: [publisher not identified], 1931.

MLA (9th ed.) Citation

Rothrock, E. P. A Preliminary Report on the Chalk of Eastern South Dakota. [publisher not identified], 1931.