@article{DAN_1976_230_2_a4,
     author = {G. M. Lyan},
     title = {On the kernel of {Poincar\'es} $\theta$-operator},
     journal = {Doklady Akademii Nauk},
     pages = {269--270},
     publisher = {mathdoc},
     volume = {230},
     number = {2},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1976_230_2_a4/}
}