MLA

Cutts, Simon, 1944-, Van Horn, Erica. Airmail envelope interiors. 2002. https://collections.library.yale.edu/catalog/2065152.

APA, 6th edition

Cutts, Simon, 1944-, & Van Horn, Erica. (2002)[Airmail envelope interiors]. https://collections.library.yale.edu/catalog/2065152.