1. M.S. Bazaraa and C.M. Shetty,Nonlinear Programming, Theory and Algorithms (Wiley, New York, 1979).
2. A. Billionnet and M. Minoux, “Maximizing a supermodular pseudoboolean function: a polynomial algorithm for supermodular cubic functions,”Discrete Applied Mathematics 12 (1985) 1–11.
3. P. Chaillou, P. Hansen and Y. Mahieu, “Best network flow bounds for the quadratic knpsack problem,” presented at NETFLOW83 International Workshop, Pisa, Italy (1983).
4. Y. Crama, “Recognition problems for special classes of pseudoboolean functions,” RUTCOR Research Report, Rutgers University (New Brunswick, NJ, 1986).
5. M.L. Fisher, G.L. Nemhauser and L.A. Wolsey, “An analysis of approximations for maximizing submodular set functions—I,”Mathematical Programming 14 (1978) 265–294.