1. Bos, P. , van Dijk, G. and Egerstrom, L. (1995). Internationale Marktmacht van Cooperaties, Campina Melkunie.
2. Vertical Integration in Competitive Markets Under Uncertainty;Carlton;Journal of Industrial Economics,1979
3. Coase, R. H. (1937). The Nature of the Firm. Economica, 386-405.
4. The Future of US Agricultural Cooperatives: A Neo-Institutional Approach;Cook;American Journal of Agricultural Economics,1995
5. Cook, M. L. (1995a). Organisational Structure and Globalisation: The Case of User Oriented Firm. University of Missouri, Columbia, Mimeo.