Sources: Uk
- Samuel L. Clemens To Charles W. and Katherine M. Dilke and Kate Field, 23 June–18 July 1872 · London, England · UCCL03718
- SLC to Chatto & Windus, 7 October 1881 · Hartford, Conn · UCCL02046
- SLC to Andrew Chatto, 1 September 1883 · Elmira, N.Y · UCCL02829
- SLC to Andrew Chatto, 17 September 1888 · Elmira, N.Y · UCCL03766
- SLC to Chatto & Windus, 27 January 1892 · Berlin, Germany · UCCL04268
- SLC to Chatto & Windus, 19 September 1899 · Sanna, Sweden · UCCL12596
- SLC to William Archer, 8 August 1900 · London, England · UCCL05848
- SLC to Charles L. Atchison, 25 September 1900 · London, England · UCCL05868
- SLC to Walpurga Ehrengarde Helena von Hohenthal Paget, December 1903 · Florence, Italy · UCCL12587
- SLC to Walpurga Ehrengarde Helena von Hohenthal Paget, December 1903 · Florence, Italy · UCCL12586
- SLC to William Archer, 22 June 1904 · Florence, Italy · UCCL06878
- SLC to Walpurga Ehrengarde Helena von Hohenthal Paget, 28 July 1904 · Lee, Mass · UCCL12588
- SLC to George Bernard Shaw, 22 December 1908 · Redding, Conn · UCCL12579
- SLC to George Bernard Shaw, 7–13 October 1909 · Redding, Conn · UCCL12580
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