@article{MS2_1971__29_166193,
     author = {Gunnar Aronsson},
     title = {Pontryagin's {Maximum} {Principle} and a {Minimax} {Problem.}},
     journal = {Mathematica Scandinavica},
     pages = {55--71},
     publisher = {mathdoc},
     volume = {29},
     year = {1971},
     zbl = {0236.49014},
     url = {http://geodesic.mathdoc.fr/item/MS2_1971__29_166193/}
}