Sources: PP3
- Samuel L. Clemens to Elisha Bliss, Jr., 2 August 1870 · Elmira, N.Y · UCCL00494
- Samuel L. Clemens to Elisha Bliss, Jr., 11 August 1870 · Elmira, N.Y · UCCL00496
- SLC to Karl Gerhardt and Hattie J. Gerhardt, 14 June 1885 · Hartford, Conn · UCCL09074
- SLC to Andrew Chatto, 14 February 1888 · New York, N.Y · UCCL03704
- SLC to Chatto & Windus, 18 August 1893 · Krankenheil, Germany · UCCL04436
- SLC to John Y. MacAlister, 23 March 1900 · London, England · UCCL05780
- SLC to Unidentified, 27 August 1901 · Saranac Lake, N.Y · UCCL06120
1