Letter from WGP to Charles Martin, January 30, 1928.
Letter from Wilburt C. Davison to Helen Kermott Penfield, September 21, 1943.
Letter from Wilder Penfield and Theodore Rasmussen to H. Rowan Gaither Jr., August 6, 1955.
Letter from Wilder Penfield to Alan Gregg, August 24, 1933.
Letter from Wilder Penfield to Alan Gregg, December 10, 1949.
Letter from Wilder Penfield to Alan Gregg, July 16, 1932.
Letter from Wilder Penfield to Alan Gregg, July 16, 1932.
Letter from Wilder Penfield to Alan Gregg, March 18, 1931.
Letter from Wilder Penfield to Alan Gregg, November 10, 1934.
Letter from Wilder Penfield to Alan Gregg, November 2, 1934.
Letter from Wilder Penfield to Alan Gregg, October 11, 1934.
Letter from Wilder Penfield to Alan Gregg, October 12, 1932.
Letter from Wilder Penfield to Alan Gregg, September 22, 1931.
Letter from Wilder Penfield to Alan Gregg.
Letter from Wilder Penfield to Alfred Newton Richards, December 1, 1931.