1. Ben-Tal, A., Eiger, G., Gershovitz, V.: Global minimization by reducing the duality gap. Math. Program. 63, 193–212 (1994)
2. Dixon, L.C.W., Szego, G.P. (eds.): Towards Global Optimization, vol. I. North-Holland, Amsterdam (1975)
3. Dixon, L.C.W., Szego, G.P. (eds.): Towards Global Optimization, vol. II. North-Holland, Amsterdam (1978)
4. Ekeland, I., Temam, R.: Convex Analysis and Variational Problems. North-Holland, Amsterdam (1976)
5. Falk, J.E.: Lagrange multipliers and nonconvex problems. SIAM J. Control 7, 534–545 (1969)