ArtLex
Art Lex: Mannerism
Artlex.com defines and describes mannerism in European art between 1520 and 1600 with examples by Michelangelo, El Greco, and others. Features links to related artists, concepts, terms, and examples.
Khan Academy
Khan Academy: Marble Sculpture Quiz
Test your knowledge of marble sculpture, past and present, as well as carving techniques in this seven-question quiz.