KKM theorem with applications to lower and upper bounds equilibrium problem in G -convex spaces. Fakhar, M.; Zafarani, J. — 2003 International Journal of Mathematics and Mathematical Sciences
Vectorial form of Ekeland-type variational principle in locally convex spaces and its applications. Eshghinezhad, S.; Fakhar, M. — 2010 Fixed Point Theory and Applications [electronic only]