@article{DE_2006_42_4_a14,
     author = {B. A. Shuvar and M. I. Kopach},
     title = {Two-sided operator inequalities with nonmonotone operators},
     journal = {Differencialʹnye uravneni\^a},
     pages = {549--552},
     publisher = {mathdoc},
     volume = {42},
     number = {4},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_2006_42_4_a14/}
}