MLA

People Assembling for a Photograph Outside a White-Walled Building, Canada, Ca. 1920-1940. 1920. https://collections.library.yale.edu/catalog/11477891.

APA, 6th edition

People assembling for a photograph outside a white-walled building, Canada, ca. 1920-1940. (1920). [Group portraits (AAT), photographic postcards (AAT), photographs (AAT)]. https://collections.library.yale.edu/catalog/11477891.