Levine, Frederick S. The Apocalyptic Vision: The Art of Franz Marc as German Expressionism [more]. New York: Harper & Row, 1979.Moffitt, J. F. "'Fighting Forms: The Fate of the Animals': The Occultist Origins of Franz Marc's �Farbentheorie'." Artibus et Historiae (Venice), no. 12 (1986), pp. 107–126. In English.
Rosenthal, Mark. Franz Marc. Munich: Prestel, 1989.
Selz, Peter. German Expressionist Painting. Berkeley and Los Angeles: University of California Press, 1957.