@article{DE_1993_29_1_a14,
     author = {M. A. Mustafin},
     title = {A condition for the basis of summation by the {Abel} method of series in root vectors of the nonselfadjoint {Sturm--Liouville} operator},
     journal = {Differencialʹnye uravneni\^a},
     pages = {116--117},
     publisher = {mathdoc},
     volume = {29},
     number = {1},
     year = {1993},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1993_29_1_a14/}
}