@article{DE_1990_26_4_a23,
     author = {G. Markhasev},
     title = {A system of nonorthogonal polynomials for constructing a solution of the {Riquier} problem in a ball for a semiharmonic equation},
     journal = {Differencialʹnye uravneni\^a},
     pages = {714--718},
     publisher = {mathdoc},
     volume = {26},
     number = {4},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1990_26_4_a23/}
}