- Islandora Repository
- Mss.B.B61_K
- Keppel, Frederick P.: To Boas. 1919 Mar. 12
- Keppel, Frederick P.: To Boas. 1925 Jan. 26
- Keppel, Frederick P.: To Boas. 1926 Mar. 13
- Keppel, Frederick P.: To Boas. 1926 Nov. 18
- Keppel, Frederick P.: To Boas. 1927 Feb. 8
- Keppel, Frederick P.: To Boas. 1930 Jan. 7
- Keppel, Frederick P.: To Boas. 1930 July 17
- Keppel, Frederick P.: To Boas. 1930 June 13
- Keppel, Frederick P.: To Boas. 1930 Mar. 7
- Keppel, Frederick P.: To Boas. 1930 May 26
- Keppel, Frederick P.: To Boas. 1930 May 29
- Keppel, Frederick P.: To Boas. 1930 Nov. 7
