@article{ZVMMF_1984_24_2_a3,
     author = {A. A. Tret'yakov},
     title = {Necessary and sufficient conditions for $P$th order optimality},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {203--209},
     publisher = {mathdoc},
     volume = {24},
     number = {2},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1984_24_2_a3/}
}