Notes from Wikiquote
As quoted in "Confidential Guide: Comedy and Things Like That," Life (January 8, 1925), p. 19; and "Chips: Not Up to Snuff" by David Brock, Times Colonist (October 24, 1955), p. 4; and Halliwell's Who's Who in the Movies (2001 ed): Art. Marx Brothers p. 297