@article{SM_1973_19_3_a0,
     author = {M. I. Vishik and A. V. Marchenko},
     title = {Boundary value problems for second-order elliptic and parabolic operators on infinite-dimensional manifolds with boundary},
     journal = {Sbornik. Mathematics},
     pages = {325--364},
     publisher = {mathdoc},
     volume = {19},
     number = {3},
     year = {1973},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1973_19_3_a0/}
}