Gemar-Koeltzsch, E., & Heibel, Y. F. (1998). German marks: Postwar drawings and prints donated to the Busch-Reisinger Museum through the German Art Dealers Association.
Lua i Stíl Chicago (17ú heag.)Gemar-Koeltzsch, Erika, agus Yule F. Heibel. German Marks: Postwar Drawings and Prints Donated to the Busch-Reisinger Museum Through the German Art Dealers Association. Cambridge, Massachusetts, 1998.
Lua MLA (8ú heag.)Gemar-Koeltzsch, Erika, agus Yule F. Heibel. German Marks: Postwar Drawings and Prints Donated to the Busch-Reisinger Museum Through the German Art Dealers Association. 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.