- Islandora Repository
- Mss.B.B61_K
- Keppel, Frederick P.: To Boas. 1939 Apr. 28
- Keppel, Frederick P.: To Boas. 1939 Jan. 19
- Keppel, Frederick P.: To Boas. 1940 Dec. 10
- Keppel, Frederick P.: To Boas. 1940 Feb. 7
- Keppel, Frederick P.: To Boas. 1940 June 26
- Keppel, Frederick P.: To Boas. 1940 Nov. 9
- Keppel, Frederick P.: To Boas. 1940 Oct. 7
- Keppel, Frederick P.: To Boas. 1941 Oct. 25
- Keppel, Frederick P.: To Boas. 1942 Mar. 6
- Keppel, Frederick P.: To Boas. undated
- Keppel, Frederick P.: To Helen R. Bryan. 1933 Mar. 30
- Keppler, Rudolph: To Boas. 1904 May 7
