The Dictionary of Art by 
A Dictionary of Modern and Contemporary Art. by 
The Oxford Companion to the Photograph by A concise encyclopedia of social/artistic aspects of photography, with photographer biographies.
The Oxford Dictionary of Art by 
The Thames and Hudson Encyclopedia of Impressionism by 
Portrait of Princess de Broglie. Oil on canvas, 1853, by J.A.D. Ingres. Courtesy of the Metropolitan Museum of Art under a Creative Commons Zero (public domain) license.
