@article{Williams1949, author = {R. M. Williams}, title = {Propositions on Intergroup Hostility and Conflict}, journal = {L. Wilson and W.L. Kolb (Eds.), Sociological Analysis. An Introductory Text and Case Book, New York (Harcourt, Brace and Co.) 1949, pp. 740-761.}, year = {1949}, }