Cite

Scenes from siege of Nanking (glass negatives) - Looking north from top of Drum Tower

MLA

Scenes from Siege of Nanking (Glass Negatives) - Looking North from Top of Drum Tower. 0AD. https://collections.library.yale.edu/catalog/12377429.

APA, 6th edition

Scenes from siege of Nanking (glass negatives) - Looking north from top of Drum Tower. (0 C.E.). [Photographs (AAT)]. https://collections.library.yale.edu/catalog/12377429.