There are many iconographical studies available. One of the classic studies is 

Erwin Panofsky. Meaning in the Visual Arts, 1955, reprinted by Harmondsworth Penguin Books, 1970.

Other selected iconographical studies

McEnroe, John and Deborah F. Pokinski. Critical Perspectives on Art History. Upper Saddle River, N.J.: Prentice Hall, 2002.

Roberts, Helene. Encyclopedia of Comparative iconography: themes depicted in works of art. Chicago : Fitzroy Dearborn, 1998.

Friedman, John Block. Medieval iconography: a research guide. New York: Garland Publishing, 1998.