Photographer, A. A. (copyright year). Title of photograph [Photograph]. Website. http://xxxxx
Zemlianichenko, A. (1997). Russian President Boris Yeltsin dancing at a rock concert [Photograph]. The Pulitzer Prizes. https://www.pulitzer.org/winners/alexander-zemlianichenko
As in-text citation:
(Zemlianichenko, 1997)
Artist, A. A. (copyright year). Title of work [Medium: Painting, drawing, sculpture, photograph, etc.]. Museum, Location. http://xxxxx
Flack, A. (1988). Islandia, goddess of the healing waters [Sculpture]. Harn Museum of Art, Gainesville, FL, United States. http://www.harn.ufl.edu/collections/8_e.html
As in-text citation:
(Flack, 1988)
Source: Publication Manual, 10.14 (examples 97 & 101)
This kind of texts is not handled well in a tool like Mendeley and is therefore recommended to do manually.