Cohn, Marjorie B. Wash and Gouache: A Study of the Development of the Materials of Watercolor. Cambridge, Mass.: Center for Conservation and Technical Studies, Fogg Art Museum, 1977.

Cohn, Marjorie B. Wash and Gouache: A Study of the Development of the Materials of Watercolor. Cambridge, Mass.: Center for Conservation and Technical Studies, Fogg Art Museum, 1977.