@article{DE_1976_12_11_a21,
     author = {K. Kh. Boimatov},
     title = {Selfadjointness of elliptic second order differential operators},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2089--2091},
     year = {1976},
     volume = {12},
     number = {11},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1976_12_11_a21/}
}