Letter from Wilder Penfield to J.C. Meakins, January 23, 1928.
Letter from Wilder Penfield to J.C. Meakins, March 2, 1928.
Letter from Wilder Penfield to J.C. Simpson, March 22, 1930.
Letter from Wilder Penfield to J.C. Simpson, October 29, 1931.
Letter from Wilder Penfield to J.C. Simpson, September 26, 1929.
Letter from Wilder Penfield to John F. Bush, July 2, 1932.
Letter from Wilder Penfield to Louis Ehret, August, 22 1930.
Letter from Wilder Penfield to Madeleine Ottmann, June 1, 1929.
Letter from Wilder Penfield to Madeleine Ottmann, November 20, 1929.
Letter from Wilder Penfield to Max Brödel, October 5, 1933.
Letter from Wilder Penfield to Max Brödel, September 19, 1933.
Letter from Wilder Penfield to Mr. & Mrs. Hodgson, June 26, 1934.
Letter from Wilder Penfield to Mr. Barnet Phillips March 23, 1934.
Letter from Wilder Penfield to Nolan D.C. Lewis, December 24, 1935.
Letter from Wilder Penfield to Nolan D.C. Lewis, January 14, 1936.