Quoted in Evan Esar, The Dictionary of Humorous Quotations (1949). Colonel Tom Parker, Elvis Presley's manager, is said to have remarked, "You don't have to be nice to people you meet on the way up if you're not coming back down again."
Quoted in Bennett Cerf, Try and Stop Me: A Collection of Anecdotes and Stories, Mostly Humorous (1944). Although this is usually credited to Mizner, the Los Angeles Times, 17 Mar. 1941, quotes Bob Oliver: "If you steal from one man, it's plagiarism. If you steal from several, it's research."