TY - BOOK AU - Ekeland,Ivar AU - Szulkin,Andrzej TI - Minimax results of Lusternik-Schnirelman type and applications . Part 2 of the proceedings of the NATO ASI "Variational methods in nonlinear problems". Montreal , 1986 SN - 2760602877 PY - 1989/// CY - Montreal PB - Universite de Montreal ER -