@article{VTGU_2012_3_a2,
     author = {V. A. Pchelintsev},
     title = {On an extremal problem},
     journal = {Vestnik Tomskogo gosudarstvennogo universiteta. Matematika i mehanika},
     pages = {22--30},
     publisher = {mathdoc},
     number = {3},
     year = {2012},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VTGU_2012_3_a2/}
}