EARL DERR BIGGERS: Barbara Gregorich, "CHARLIE CHAN'S POPPA: The Life of Earl Derr Biggers," Timeline, a publication of the Ohio Historical Society, January-February 1999 (Volume 16, Number 1)
Barbara Gregorich, "CHARLIE CHAN'S POPPA: The Life of Earl Derr Biggers," Timeline, a publication of the Ohio Historical Society, January-February 1999 (Volume 16, Number 1)