Kliemt, H.1986. The veil of insignificance. European Journal of Political Economy2:333-344.
2.
Oliver, P.
, G. Marwell, and R. Teixeira. 1985. A theory of the critical mass. I. Interdependence, group heterogeneity, and the production of collective action. American Journal of Sociology91:522-556.
3.
Tietzel, M.
, M. Weber, and O. F. Bode. 1991. Die Logik der sanften Revolution [The logic of the soft revolution]. Tübingen: Mohr.