1. Burt, R.S., 1984. Structural holes: The social structure of competition. Harvard Univ. Press, Cambridge, MA.
2. Structural balance: a generalization of Heider's theory;Cartwright;Psychological Review,1956
3. Davis, J.A., Leinhardt, S., 1972. The structure of positive relations in small groups. In: Berger, J., Zelditch, M., Anderson, B. (Eds.), Sociological Theories in Progress, Vol. 2, Houghton Mifflin, Boston, MA, pp. 218–51.
4. Transitivity and the path census in sociometry;Fershtman;Journal of Mathematical Sociology,1985
5. A method for detecting structure in sociometric data;Holland;Am. J. Sociol.,1970