Sources: NjNH2
- SLC to G. K. Jewett, 12 October 1871 · Hartford, Conn · UCCL12952
- Samuel L. Clemens to Olivia L. Clemens, 15 September 1872 · London, England · UCCL00807
- Samuel L. Clemens to Andrew Chatto, 28 April 1877 · Baltimore, Md · UCCL12932
- Samuel L. Clemens to Elisha Bliss, Jr., 6 March 1879 · Paris, France · UCCL11673
- SLC to Karl and Hattie J. Gerhardt, 21 November 1881 · Hartford, Conn · UCCL02094
- SLC to Horace Russell, 16 November 1882 · Hartford, Conn · UCCL02306
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