@article{UMJ_2017_3_2_a3,
     author = {Vitalii V. Arestov},
     title = {A characterization of extremal elements in some linear problems},
     journal = {Ural mathematical journal},
     pages = {22--32},
     publisher = {mathdoc},
     volume = {3},
     number = {2},
     year = {2017},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/UMJ_2017_3_2_a3/}
}