Letter from Herbert S. Holt to Wilder Penfield, July 31, 1934.
Letter from Hugh Auchincloss to Wilder Penfield, November 15, 1934.
Letter from J. Simpson to A.P.S. Glassco, July 30, 1931.
Letter from J. Simpson to Wilder Penfield, July 30, 1931.
Letter from J. Simpson to Wilder Penfield, June 25, 1930.
Letter from J.C. Simpson to Wilder Penfield, March 18, 1930.
Letter from J.C. Simpson to Wilder Penfield, October 28, 1931.
Letter from J.F. McIntosh to Wilder Penfield, June 17, 1944.
Letter from J.F. McIntosh to Wilder Penfield, September 9, 1944.
Letter from John Fulton to Wilder Penfield, September 29, 1934.
Letter from John R. Yates to Wilder Penfield, August 21, 1928.
Letter from John R. Yates to Wilder Penfield, July 25, 1928.
Letter from Joseph M. McDaniel Jr. to D.L. Thomson December 8, 1955.
Letter from Joseph M. McDaniel Jr. to Wilder Penfield, November 7, 1955.
Letter from Kazimierz Orzechowski to Wilder Penfield, September 24, 1934