Source data found1. WWW REBIUN, 25/05/2022 Allen, Douglas, autor
2. N.C.Wyeth: the collected paintings, illustrations and murals, 1972 Port. (Douglas Allen)
3. National Museum of Wildlife Art online, June 25, 2020 (Douglas Allen. Collecionista de las obras de N. C. Wyeth, en 1972 escribe con su hijo el libro "N. C. Wyeth, The Collected Paintings, Illustrations and Murals."
4. Wyeth, N.C. N.C. Wyeth, 1984 Port. (Douglas Allen)