@article{DE_1973_9_12_a18,
     author = {O. A. Kastritsa},
     title = {The structure of matrices of coefficients of linear spherically combined systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2248--2250},
     publisher = {mathdoc},
     volume = {9},
     number = {12},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1973_9_12_a18/}
}