MLA

Peterson, E. Frank. Map of Tripp County, South Dakota / Compiled and Drawn from Official Records by E. Frank Peterson, Lake Andes, S.D. E. Frank Peterson?], 0AD. https://collections.library.yale.edu/catalog/15814756.

APA, 6th edition

Peterson, E. F. (0 C.E.). Map of Tripp County, South Dakota / compiled and drawn from official records by E. Frank Peterson, Lake Andes, S.D. [Maps]. E. Frank Peterson?], https://collections.library.yale.edu/catalog/15814756.