1. Blalock A: Letter
2. Clatworthy, HW Jr: Personal recollections and personal communication, Columbus, OH, 1990–1997
3. Documents, correspondence, transcribed recollections;Cloud,1994
4. Documents, extensive correspondence;Coe,1940
5. Holcomb GW Jr: Personal recollections and personal communication, Nashville, TN, 1990–1997