Wallace, David. "The Round Table". Capital of the World: A Portrait of New York City in the Roaring Twenties. Guilford, CT: Lyons Press. p. 168. ISBN 978-0-7627-7010-6
Hopper, Hedda. "Hedda Hopper's Hollywood". The Harrisburg Telegraph. August 10, 1944. "Harpo's adopted his second son and named him Alexander Marx. His first boy is William Woollcott. He's done all right for his old friend, the late Alexander Woollcott."
