Alaska road map and travel guide / [prepared for] Union Oil Company of California.
MLA
Service, Northwest Mapping. Alaska Road Map and Travel Guide / [Prepared for] Union Oil Company of California. Northwest Mapping Service, 0AD. https://collections.library.yale.edu/catalog/15821730.
APA, 6th edition
Service, N. M. (0 C.E.). Alaska road map and travel guide / [prepared for] Union Oil Company of California. [Road maps]. Northwest Mapping Service, https://collections.library.yale.edu/catalog/15821730.