@article{MOMA_1958__62_177031,
     author = {Raymond M. Redheffer},
     title = {Maximum {Principles} and {Duality.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {56--75},
     year = {1958},
     volume = {62},
     zbl = {0094.29901},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1958__62_177031/}
}