1. F. S. Hillier and G. J. Lieberman, Introduction to Operations Research, Holden-Day, San Francisco, 1974.
2. M. Zeleny, Multiple Criteria Decision Making, McGraw Hill, New York, 1982.
3. R. E. Steuer, Multiple Criteria Optimization Theory, Computation, and Application, Wiley, New York, 1986.
4. A. S. Bryk and S. W. Raudenbush, Hierarchical Linear Models, Sage, London, 1992.
5. G. H. Tzeng, H. F. Wang, U. P. Wen, and P. L. Yu, Multiple Criteria Decision Making, Springer-Verlag, Amsterdam, 1994.