Lull, Richard Swann (1917). "XXXVII: The Evolution of Man". Organic Evolution (1929ed.). New York: The Macmillan Company. pp.641–86. Archived from the original on 2024-03-28. Retrieved 2023-03-19– via Google Books.
Lull, Richard Swann (1917). "XXXVII: The Evolution of Man". Organic Evolution (1929ed.). New York: The Macmillan Company. pp.641–86. Archived from the original on 2024-03-28. Retrieved 2023-03-19– via Google Books.