Sources: PP
- SLC to Karl Gerhardt, 5 September 1885 · Elmira, N.Y · UCCL11710 PP, MB
- Andrew W. Tuer to SLC, November 1899 · UCLC48207 PP
- SLC to Francis E. Bliss, 16 January 1900 · London, England · UCCL05748 PP
- SLC to Percy Spalding, July 1900 · London, England · UCCL11463 PP
- William D. Howells to SLC, 28 December 1902 · New York, N.Y. · UCLC33648 PP
- SLC to IVL, 17-18 February 1904 · Florence, Italy · UCCL04218 PP
- SLC to Unidentified, 21 June 1904 · Florence, Italy · UCCL06852 PP
- SLC to Unidentified, 6 August 1905 · Dublin, N.H · UCCL09625 PP
- SLC to Howard Pyle, 10 December 1905 · New York, N.Y · UCCL11461 PP
- SLC to George B. Harvey, Unknown date · Unknown place · UCCL09628 PP
- Harper & Bros. and George B. Harvey to SLC, 1 August 1906 · New York, N.Y. · UCLC35527 PP
- SLC to Charlotte Teller, 10 October 1906 · New York, N.Y · UCCL09629 PP
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