@article{FAA_1972_6_4_a9,
     author = {I. S. Gudovich and S. G. Krein},
     title = {Elliptic boundary problems for the system},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {75--76},
     publisher = {mathdoc},
     volume = {6},
     number = {4},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_1972_6_4_a9/}
}