1. ‘Core’ and ‘extended’ social networks in relation to health and illness;Hammer;Soc. Sci. Med.,1983
2. The Division of Labour in Society;Durkheim,1934
3. Gemeinschaft and Gesselschaft;Tonnies,1955
4. Urbanisation as a way of life;Wirth;Am. J. Sociol.,1973
5. The kinship system of the contemporary United States,1964