1. Darwin D. Martin, The First to Make a Card Ledger: Story of the Larkin Card Indexes (Buffalo, N.Y., 1932).
2. For histories of the Larkin Company, see Margot C. Adams-Webber, “Soap-Slingers, Drummers, and Agents: Larkin Company Merchandising 1875–1885,” Marketing History Knows No Boundaries: Proceedings of the 8th Conference on Historical Research in Marketing and Marketing Thought (East Lansing: Michigan State University, 1997), 123–32; Daniel I. Larkin, John D. Larkin: A Business Pioneer (Buffalo, N.Y.: Daniel I. Larkin, 1998); Howard R. Stanger, “From Factory to Family: The Creation of a Corporate Culture in the Larkin Company of Buffalo, New York,” Business History Review 74, no. 3 (Autumn 2000), 407–33; Howard R. Stanger, “Ourselves: Welfare Capitalism in the Larkin Company, 1900–1939,” in LERA Annual Meeting Proceedings (Washington, D.C.: Industrial Relations Research Association, 2003), 50–58; Howard R. Stanger, “Welfare Capitalism in the Larkin Company, 1900–1925,” New York History 86, no. 2 (Spring 2005), 210–58; Howard R. Stanger, “The Larkin Clubs of Ten: Consumer Buying Clubs and Mail-Order Commerce, 1890–1940,” Enterprise & Society 9, no. 1 (2008), 125–64; Howard R. Stanger, “Failing at Retailing: The Decline of the Larkin Company, 1918–1942,” Journal of Historical Research in Marketing 2, no. 1 (2010), 9–40.
3. Stanger, “From Factory to Family,” 407–8.
4. For an explanation of the Larkin Idea, see “Selling Talk,” B76-1, box 1, folder 2, Darwin D. Martin Papers, Research Library, Buffalo History Museum. The idea is also explained in the numerous Larkin Company catalogues that were sent to customers. See The Larkin Idea (Buffalo, N.Y.: Larkin Soap Company, 1901).
5. By 1915, each of the company's catalogues included the “Larkin Club-of-Ten Members' Agreement” and information about how to form a Larkin Club.