According to Kevin Brownlow's "The Parade's Gone By", Dwan thought he'd directed over 1400 films, including one-reelers, between his arrival in the industry (circa 1909) and his final film in 1961.
Biography in: John Wakeman, editor. "World Film Directors, Volume One, 1890-1945". Pages 283-291. New York: The H.W. Wilson Company, 1987.
Interviewed in "Talking to the Piano Player: Silent Film Stars, Writers and Directors Remember" by Stuart Oderman (BearManor Media).
Interviewed in Peter Bogdanovich's "Who the Devil Made It: Conversations With Robert Aldrich, George Cukor, Allan Dwan, Howard Hawks, Alfred Hitchcock, Chuck Jones, Fritz Lang, Joseph H. Lewis, Sidney Lumet, Leo McCarey, Otto Preminger, Don Siegel, Josef von Sternberg, Frank Tashlin, Edgar G. Ulmer, Raoul Walsh." NY: Alfred A. Knopf, 1997.