MLA

Carter, [---?], Dr. [Photograph of petroglyphs]. Box 1 | Folder 19. undated. https://collections.library.yale.edu/catalog/2017624.

APA, 6th edition

Carter, [---?], Dr. (["Box 1 | Folder 19"])(undated)[[Photograph of petroglyphs]]. https://collections.library.yale.edu/catalog/2017624.