@article{SM_1991_69_1_a6,
     author = {S. Ya. Yakubov},
     title = {Multiple completeness for systems of operator bundles and elliptic boundary value problem},
     journal = {Sbornik. Mathematics},
     pages = {99--119},
     publisher = {mathdoc},
     volume = {69},
     number = {1},
     year = {1991},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1991_69_1_a6/}
}