MLA

Clapp, Frederick Mortimer, 1879-1969. "Photos taken in Venice after 1st world war with some of Tim and Maud and of Constance Fletcher and H.D.". Box 115. 1894-1967. https://collections.library.yale.edu/catalog/2055469.

APA, 6th edition

Clapp, Frederick Mortimer, 1879-1969. (["Box 115"])(1894-1967)["Photos taken in Venice after 1st world war with some of Tim and Maud and of Constance Fletcher and H.D."]. https://collections.library.yale.edu/catalog/2055469.