DiMaggioPGaripF (2012) Network effects and social inequality. Annual Review of Sociology38(1): 93–118.
2.
MabogunjeAL (1970) Systems approach to a theory of rural-urban migration. Geographical Analysis2(1): 1–18.
3.
MertonR (1967 [1949]) On sociological theories of the middlerange. In: MertonR (ed.) On Theoretical Sociology: Five Essays Old and New. New York, NY: The Free Press, pp. 39–72.