RT Journal Article SR 00 A1 Mordukhovich, B.S. T1 An abstract extremal principle with applications to welfare economics JF Journal of Mathematical Analysis and Applications YR 2000 FD 2000 SP 187 OP 216 PB Elsevier SN 1096-0813 LK https://pure.iiasa.ac.at/id/eprint/5965/