MLA

Company, Northern Pacific Railroad. Sectional Land Map of a Part of North Dakota : the Map in the District Which It Covers, Shows the Northern Pacific Railroad Lands for Sale .... Northern Pacific Railroad Co.?, 1887. https://collections.library.yale.edu/catalog/15814737.

APA, 6th edition

Company, N. P. R. (1887). Sectional land map of a part of North Dakota : the map in the district which it covers, shows the Northern Pacific Railroad lands for sale .... [Maps]. Northern Pacific Railroad Co.?, https://collections.library.yale.edu/catalog/15814737.