Leonard, John William; Downs, Winfield Scott; Lewis, M. M. Who's who in Engineering. John W. Leonard Corporation. 1922-01-01 [2017-09-14]. (原始内容存档于2019-06-08) (英语).
Leonard, John William; Downs, Winfield Scott; Lewis, M. M. Who's who in Engineering. John W. Leonard Corporation. 1922-01-01 [2017-09-14]. (原始内容存档于2019-06-08) (英语).