Cite

Aspen. Colorado No. 9.

MLA

Ingersoll, Ernest, 1852-1946, Jackson, William Henry, 1843-1942. Aspen. Colorado No. 9.. https://collections.library.yale.edu/catalog/2018650.

APA, 6th edition

Ingersoll, Ernest, 1852-1946, & Jackson, William Henry, 1843-1942. [Aspen. Colorado No. 9.]. https://collections.library.yale.edu/catalog/2018650.