George Gaylord Simpson (1967). “The Meaning of Evolution: A Study of the History of Life and of Its Significance for Man”, p.345, Yale University Press
George Gaylord Simpson (1967). “The Meaning of Evolution: A Study of the History of Life and of Its Significance for Man”, p.311, Yale University Press
George Gaylord Simpson (1967). “The Meaning of Evolution: A Study of the History of Life and of Its Significance for Man”, p.345, Yale University Press