Mark Twain, Michael Barry Frank, Robert Pack Browning, Lin Salamo, Frederick Anderson, Mark Twain (1980). “Mark Twain's Notebooks & Journals, Volume III: (1883-1891)”, p.424, Univ of California Press
Mark Twain, Michael Barry Frank, Robert Pack Browning, Lin Salamo, Frederick Anderson, Mark Twain (1980). “Mark Twain's Notebooks & Journals, Volume III: (1883-1891)”, p.399, Univ of California Press