Kobs, J. (1979). Profitable direct marketing: How to start, improve, or expand any direct marketing operation ... plus 11 detailed case studies of prominent direct marketing companies. NTC Business Books.
Chicago-viite (17. p.)Kobs, Jim. Profitable Direct Marketing: How to Start, Improve, or Expand Any Direct Marketing Operation ... Plus 11 Detailed Case Studies of Prominent Direct Marketing Companies. Chicago, Ill: NTC Business Books, 1979.
MLA-viite (9. p.)Kobs, Jim. Profitable Direct Marketing: How to Start, Improve, or Expand Any Direct Marketing Operation ... Plus 11 Detailed Case Studies of Prominent Direct Marketing Companies. NTC Business Books, 1979.
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