Sources: DSI
- SLC to Daniel Whitford, 14 August 1885 · Elmira, N.Y · UCCL10441 DSI
- Abbott H. Thayer to SLC, 18 June 1901 · Monadnock, N.H. · UCLC48130 DSI
- SLC to John White Alexander, 28 November 1902 · New York, N.Y · UCCL13562 DSI
- Abbott H. Thayer to SLC, 10 February 1906 · Monadnock, N.H. · UCLC48131 DSI
- Abbott H. Thayer to SLC, Unknown date · UCLC48132 DSI
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