Sumner, C., & Palmer, B. W. (1988). The papers of Charles Sumner, 1811-1874. Chadwyck-Healey.
Lua i Stíl Chicago (17ú heag.)Sumner, Charles, agus Beverly Wilson Palmer. The Papers of Charles Sumner, 1811-1874. Alexandria, VA: Chadwyck-Healey, 1988.
Lua MLA (8ú heag.)Sumner, Charles, agus Beverly Wilson Palmer. The Papers of Charles Sumner, 1811-1874. Chadwyck-Healey, 1988.
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