MLA Style - Works Cited entry
Cite the artists' name; title of the artwork, italicized; the date of composition; the institution and city in which the artwork is located; database name, italicized; the medium (Web); your date of access.
Example with no artist name:
Apron. Fourth quarter, 19th Century. Metropolitan Museum of Art, New York.
ARTstor. library.artstor.org/#/asset/ABROOKLYNIG_10312349725. Accessed
15 Jul. 2017.
Example with artist name:
Raphael. Saint George and the Dragon. 1504. Musée du Louvre, Paris. ARTstor.
library.artstor.org/#/asset/LESSING_ART_10310119688. Accessed 15 Jul.