"The Ballot or The Bullet (Cleveland Version)". Malcolm X's speech at Cory Methodist Church in Cleveland, Ohio (April 3, 1964) as quoted in "Malcolm X Speaks: Selected Speeches and Statements" edited by George Breitman (pp. 23-44), 1965.
Gregor Mendel, Alain F. Corcos, Floyd V. Monaghan (1993). “Gregor Mendel's Experiments on Plant Hybrids: A Guided Study”, p.69, Rutgers University Press