Who's Who in America (1908–09), Vol. 5. Chicago: A. N. Marquis Company, p. 125. (Becker.)
2.
Who's Who in America (1914–15), Vol. 8. Chicago: A. N. Marquis Company. p. 2596. (Witthaus.)
3.
They Escaped the Hangman (Notable American Trials). By Francis X. Busch London: Arco Publications, Ltd. 1957. pp. 103–160. (The Rice-Patrick case.)
4.
American Medical Biographies. By Howard A. Kelly and Walter L. Burrage. Baltimore: The Norman Remington Company. 1920 pp. 1251–1252. (Article on Witthaus by Thomas Hall Shastid.)
5.
Obituary (1916) J. Amer. Med. Ass.66, T32.
6.
Obituary (1915) Med. Record88, 1100.
7.
0. Resolution in Memory of Rudolph August Witthaus by the Faculty of Cornell University Medical College (1916) Science, 43 N.S., 527–528.
8.
Famous American Poison Mysteries. By Edward H. Smith. London: Hurst Blackett, Ltd. 1926. Passim.
9.
A Doctor's Memories. By Victor C. Vaughn. Indianapolis: TheBobbs-Merrill Company. 1926 pp. 306–308.
10.
Memoirs ol a Small Town Surgeon. By John B. Wheeler. Garden City, New York: Garden City Publishing Company. 1935. p. 164 and pp. 169–170.
