@article{DE_2006_42_10_a16,
     author = {T. E. Moiseev},
     title = {On a version of the directional derivative problem},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1434--1436},
     publisher = {mathdoc},
     volume = {42},
     number = {10},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_2006_42_10_a16/}
}