@article{DE_1986_22_10_a13,
     author = {U. Raitums},
     title = {Transition to convex families of admissible operators in optimal control problems for elliptic equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1778--1785},
     publisher = {mathdoc},
     volume = {22},
     number = {10},
     year = {1986},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1986_22_10_a13/}
}