@article{IVM_1985_5_a5,
     author = {\`E. M. Saak},
     title = {Summation of {Neumann} series},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {31--33},
     publisher = {mathdoc},
     number = {5},
     year = {1985},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1985_5_a5/}
}