Max Beckmann Briefe. Herausgegeben von Klaus Gallwitz, Uwe M. Schneede und Stephan von Wiese unter Mitarbeit von Barbara Golz. Band III: 1937–1950. Bearbeitet von Klaus Gallwitz unter Mitarbeit von Ursula Harter. München/Zürich 1996, Nr. 955, 956, 957;Morton D. May 1975 im Interview mit Walter Barker, Typoskript, Saint Louis Art Museum Archives: „(...) when Beckmann moved to N.Y. I introduced Maurice and his wife to Beckmann, and Beckmann had seen a number of his paintings at my house and before Beckmann met him he told me that he thought that America was lucky to have a painter like Freedman (...) and they became very good friends in N.Y.”;