1. Anderson, J. Path analysis: A new approach to modeling health service delivery systems. (Institute for the Study of Social Change Working Paper No. 45.) Lafayette, Ind.: Purdue University, 1971.
2. Berrien, F. K.General and social systems. New Brunswick, N.J.: Rutgers University Press, 1970.
3. Bertalanffy, L. V. General systems theory.Yearbook of the society for general systems research, 1956,1, 1?10.
4. Boyle, R. Path analysis and ordinal data.American Journal of Sociology, 1970,75, 461?480.
5. Goody, J., Irving, B., & Tahany, N. Hierarchical linkage analysis and path analysis, in discussion of causal inferences concerning inheritance and property.Human Relations, 1971,24, 295?314.