The five great rules of selling. Whiting, Percy H. Selling. HF5438 .W56 1947 658.8 WHE An expanded version of the work priv. pub. by the author in 1939. "List of visual aids": p. 253-257. New York ; London : McGraw-Hill Book Co., 1947. 1947. 1947 Text x, 261 p. ; eng