1. Bengtsson, M. and Kock, S. 1999. “Co-operation and Competition in Relationships among Competitors in Business Networks.” The Journal of Business and Industrial Marketing. Vol 14, No 3: 178–194
2. Brandenburger, A. M. and Nalebuff B. J. 1996. Co-opetition, New York: Doubleday.
3. Heiss, J. 1990. “Social roles.” In Rosenberg, M. and Turner, R. H. (Eds.), Social Psychology: Sociological Perspectives, New Brunswick, NJ: Transaction: 94–129,
4. Kahn, R. L., Wolfe, D. M., Quinn, R. P. and Snoek, J. D., 1964. Organisational Stress: Studies in Role Conflict and Ambiguity, New York: John Wiley & Sons.
5. Merton, R. K., 1957. “The Role Set: Problem in Sociological Theory.” British Journal of Sociology, VIII, (June): 113 ff.