1. American Philosophical Society, 1929a. Stern letter to Muller, August 8, 1929.
2. American Philosophical Society, 1929b. Muller letter to Stern, October 3, 1929.
3. American Philosophical Society, 1929c. Stern letter to Muller, October 23, 1929.
4. American Philosophical Society, 1946. Muller Letter to Spencer and Stern, September 13, 1946.
5. American Philosophical Society, 1946/1947. Curt Stern Papers, Hermann J. Muller File, Philadelphia. 〈http://amphilsoc.org〉.