@article{DAN_1981_260_1_a4,
     author = {N. La\v{z}eti\'c},
     title = {On the derivatives of partial sums of expansions in eigenfunctions and associated functions of nonselfadjoint operators of {Sturm--Liouville} type},
     journal = {Doklady Akademii Nauk},
     pages = {22--26},
     publisher = {mathdoc},
     volume = {260},
     number = {1},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1981_260_1_a4/}
}