@article{DAN_1961_137_2_a3,
     author = {S. P. Geisberg},
     title = {Certain properties of summation methods},
     journal = {Doklady Akademii Nauk},
     pages = {265--267},
     publisher = {mathdoc},
     volume = {137},
     number = {2},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_137_2_a3/}
}