@article{KUKZ_1976_13_13_a13,
     author = {B. A. Kats},
     title = {A method for estimating the number of linearly independent solutions of boundary value problems},
     journal = {Trudy seminara po kraevym zada\v{c}am},
     pages = {120--127},
     publisher = {mathdoc},
     volume = {13},
     number = {13},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/KUKZ_1976_13_13_a13/}
}