Der öffentliche Feind
There's a reference to James Cagney ("The Public Enemy", 1931) and grapefruit - Bud (Preston Foster) to girl in the street "why don't you let me sit across from ya, and squirt grapefruit juice in your eye, like they do in the movies". That refers to the notorious scene in The Public Enemy, in which Cagney viciously mashes a grapefruit into the face of Mae Clarke at breakfast.