@article{DAN_1977_234_2_a14,
     author = {N. N. Popov},
     title = {Geometric ergodicity conditions for countable {Markov} chains},
     journal = {Doklady Akademii Nauk},
     pages = {316--319},
     publisher = {mathdoc},
     volume = {234},
     number = {2},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1977_234_2_a14/}
}