Cite

Printed maps and a letter from Joe Warner, hunter and guide, to Dr. Oastler dated 1915 Mar 16, which were previously in the "Maps" envelope at the front of the 1914 Mount Robson Trip, Album I

MLA

Oastler, Frank Richard, 1871-1936. Printed maps and a letter from Joe Warner, hunter and guide, to Dr. Oastler dated 1915 Mar 16, which were previously in the "Maps" envelope at the front of the 1914 Mount Robson Trip, Album I. Box 69, folder 70. 1915, undated. https://collections.library.yale.edu/catalog/15831930.

APA, 6th edition

Oastler, Frank Richard, 1871-1936. (["Box 69, folder 70"])(1915, undated)[Printed maps and a letter from Joe Warner, hunter and guide, to Dr. Oastler dated 1915 Mar 16, which were previously in the "Maps" envelope at the front of the 1914 Mount Robson Trip, Album I]. https://collections.library.yale.edu/catalog/15831930.