APA-viite (7. p.)
MarketingSherpa, Inc, & ebrary, Inc. (2003). Proven online subscription sales tactics: 31 case studies and 25 tactics to get more paid subscribers. MarketingSherpa, Inc..
Chicago-viite (17. p.)
MarketingSherpa, Inc, ja Inc ebrary. Proven Online Subscription Sales Tactics: 31 Case Studies and 25 Tactics to Get More Paid Subscribers. Portsmouth, R.I.: MarketingSherpa, Inc., 2003.
MLA-viite (9. p.)
MarketingSherpa, Inc, ja Inc ebrary. Proven Online Subscription Sales Tactics: 31 Case Studies and 25 Tactics to Get More Paid Subscribers. MarketingSherpa, Inc., 2003.
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