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
Dr. Ivan Van Sertima, John Henrik Clarke “Dr. Ivan Van Sertima- 8 DVD video lectures: 8 DVDs, Best viewed on wifi on phones or tablets. iPads or Android (use google Play Book app to view. Gmail account required)”, Clemson Brown