1. Adams, H. B. (1888). History of cooperation in the US. Hopkins Press.
2. Adams, W. C. (2015). Conducting semi-structured interviews. In K. E. Newcomer, H. P. Hatry, & J. S. Wholey (Eds.), Handbook of practical program evaluation (4th ed., pp. 492–505). Jossey-Bass. https://doi.org/10.1002/9781119171386.ch19
3. Bakken, H. H., & Schaars, M. A. (1937). The economics of cooperative marketing. MacGraw-Hill Book Company.
4. Birchall, J. (2003). Rediscovering the cooperative advantage: Poverty reduction through self-help. International Labour. Organization.
5. Blankertz, D. F. (1940). Marketing cooperatives. The Ronald Press Company.