@article{DAN_1965_161_6_a6,
     author = {Yu. I. Lyubich},
     title = {General theorems on quadratic relaxation},
     journal = {Doklady Akademii Nauk},
     pages = {1274--1277},
     publisher = {mathdoc},
     volume = {161},
     number = {6},
     year = {1965},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1965_161_6_a6/}
}