1. Graph theory: an algorithmic approach;Christofides,1975
2. Beresnev VL, Gimadi EKh, Dementyev VT. Extremal standardization problems. Novosibirsk: Nauka, 1978 [in Russian].
3. Goldengorin B. Requirements of standards: optimization models and algorithms. ROR, Hoogezand, The Netherlands, 1995.
4. Specially structured uncapacitated facility location problems;Jones;Operations Research,1995
5. The assortment problem with nonlinear cost functions;Pentico;Operations Research,1976