Howland, Richard H. Programmed learning aid for principles of salesmanship / [electronic resource] / Richard H. Howland ; coordinating editor, Roger H. Hermanson.. — Homewood, IL : : Learning Systems,, 1972.. — xi, 140 p. ISBN: 025601261X Subjects--Topical Terms: Selling--Programmed instruction. LC Class. No.: HF5438.2'H69