@article{IVM_1982_3_a1,
     author = {A. I. Vahabov},
     title = {Double expansion in {Fourier} series in principal functions of a~nonselfadjoint elliptic operator},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {8--13},
     publisher = {mathdoc},
     number = {3},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1982_3_a1/}
}