1. Blau, J. (1980). When Weak Ties are Structured. Unpublished manuscript, Department of Sociology, State University of New York, Albany.
2. Cross, R. L. & Thomas, R. J. (2009). Driving Results Through Social Networks: How Top Organizations Leverage Networks for Performance and Growth. San Francisco: Jossey- Bass.
3. Gross, P. (1994). Die Multioptionsgesellschaft. Frankfurt a. M.: Suhrkamp.
4. Piketty, T. (2013). Le capital au XXIe siècle. Paris: Éditions du Seuil.
5. Stiglitz, J. E. (2016). The Great Divide. Penguin Random House UK.