Michael E. Porter «Competitive Strategy: Techniques for Analyzing Industries and Competitors» (New York: The Free Press, 1998, pp. 35–38).
96
Teresa Novellino «To Catch Amazon, Jet.com Needs to Fuel Up, Find Niches», New York Business Journal, July 30, 2015: bizjournals.com/newyork/news/2015/07/30/to-catch-amazon-jet-com-needs-to-fuel-up-find.html
