Sources: UkReU
- Samuel L. Clemens to Andrew Chatto, 27 March 1880 · Hartford, Conn · UCCL00743
- Samuel L. Clemens to Chatto and Windus, 25 April 1880 · Hartford, Conn · UCCL00779
- Samuel L. Clemens to Chatto and Windus, 1 May 1880 · Hartford, Conn · UCCL00783
- SLC to Chatto & Windus, 25 August 1881 · Boston, Mass · UCCL01591
- SLC to Chatto & Windus, 27 November 1881 · Montreal, Canada · UCCL02100
- SLC to Chatto & Windus, 29 May 1882 · Hartford, Conn · UCCL01623
- SLC to Chatto & Windus, 28 February 1883 · Hartford, Conn · UCCL01648
- SLC to Andrew Chatto, 11 June 1883 · Hartford, Conn · UCCL00813
- SLC to Andrew Chatto, 12 November 1883 · Hartford, Conn · UCCL00863
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