@article{MMO_1979_40_a4,
     author = {A. V. Arkhangel'skiǐ},
     title = {The spectrum of frequencies of a~topological space and the product operation},
     journal = {Trudy Moskovskogo matemati\v{c}eskogo ob\^{s}estva},
     pages = {171--206},
     publisher = {mathdoc},
     volume = {40},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MMO_1979_40_a4/}
}