Letter from Wilder Penfield to Dr. and Mrs. Lewis Reford, June 26, 1934.
Letter from Wilder Penfield to Dr. Charles F. Martin, September 23, 1933.
Letter from Wilder Penfield to Dr. Frederic MacKay, January 13, 1928.
Letter from Wilder Penfield to Dr. Nolan D.C. Lewis, July 5, 1935.
Letter from Wilder Penfield to Dr. William C. Quinby, March 5, 1928.
Letter from Wilder Penfield to E.W. Beatty, July 4, 1934.
Letter from Wilder Penfield to E.W. Beatty, September 6, 1934.
Letter from Wilder Penfield to Edward Archibald, February 24, 1928.
Letter from Wilder Penfield to Edward Archibald, January 18, 1929.
Letter from Wilder Penfield to Edward Archibald, January 30, 1928.
Letter from Wilder Penfield to Edward Archibald, July 17, 1927.
Letter from Wilder Penfield to Edward Archibald, June 30, 1927.
Letter from Wilder Penfield to Edward Archibald, November 10, 1927.
Letter from Wilder Penfield to Edward Archibald, September 16, 1927.
Letter from Wilder Penfield to Emma M. Abbett, March 10, 1928.