MLA

of New York, American Geographical Society. Adriatic [Sea Region]. American Geographical Society, 0AD. https://collections.library.yale.edu/catalog/15238019.

APA, 6th edition

of New York, A. G. S. (0 C.E.). Adriatic [Sea region]. [Maps]. American Geographical Society, https://collections.library.yale.edu/catalog/15238019.