Sources: MoPeS
- Samuel L. Clemens to Francis E. Bliss, 9–12 July 1872 · New Saybrook, Conn · UCCL00767
- Samuel L. Clemens to Elisha Bliss, Jr., 18 November 1875 · Hartford, Conn · UCCL01281
- Samuel L. Clemens to Elisha Bliss, Jr., 16 May 1876 · Hartford, Conn · UCCL01335
- SLC to American Publishing Co., 23 March 1881 · Hartford, Conn · UCCL01930
- SLC to George H. Himes, 17 January 1886 · Hartford, Conn · UCCL03356
- SLC to Francis E. Bliss, 1 May–31 July 1897 · Unknown place · UCCL02359
- SLC per Olivia L. Clemens to Walter Bliss, 9 January 1898 · Vienna, Austria · UCCL05333
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