Cite

The Rocky Mountains. No. 48

MLA

Ingersoll, Ernest, 1852-1946, Jackson, William Henry, 1843-1942. The Rocky Mountains. No. 48. https://collections.library.yale.edu/catalog/2018699.

APA, 6th edition

Ingersoll, Ernest, 1852-1946, & Jackson, William Henry, 1843-1942. [The Rocky Mountains. No. 48]. https://collections.library.yale.edu/catalog/2018699.