University of Minnesota. Center for Comparative Studies in Technological Development and Social Change, University of Minnesota. Department of Political Science, Holt, R. T., & Turner, J. E. (1972). The Methodology of comparative research: A symposium from the Center for Comparative Studies in Technological Development and Social Change and the Department of Political Science, University of Minnesota (First edition.). Free Press.

University of Minnesota. Center for Comparative Studies in Technological Development and Social Change, University of Minnesota. Department of Political Science, Robert T. Holt, и John Elliot Turner. The Methodology of Comparative Research: A Symposium from the Center for Comparative Studies in Technological Development and Social Change and the Department of Political Science, University of Minnesota. First edition. New York: Free Press, 1972.

University of Minnesota. Center for Comparative Studies in Technological Development and Social Change, et al. The Methodology of Comparative Research: A Symposium from the Center for Comparative Studies in Technological Development and Social Change and the Department of Political Science, University of Minnesota. First edition. Free Press, 1972.