↑ Rozendaal, Neal (2012). Duke Slater: Pioneering Black NFL Player and Judge . Jefferson, North Carolina: McFarland & Company, Inc. p. 131. ISBN978-0-7864-6957-4。
↑ Partsch-Bergsohn, Isa (1994). Modern Dance in Germany and the United States: Crosscurrents and Influences . Harwood Academic Publishers. p. 65. ISBN978-3-7186-5557-1。