APA (7th ed.) Citation

Schmalenbach, W., Helfenstein, J., & Frey, S. (1993). Paul Klee (1879-1940).

Chicago Style (17th ed.) Citation

Schmalenbach, Werner, Josef Helfenstein, and Stefan Frey. Paul Klee (1879-1940). Düsseldorf, 1993.

MLA (9th ed.) Citation

Schmalenbach, Werner, et al. Paul Klee (1879-1940). 1993.