@article{MO_2000_2_a2,
     author = {L. V. Mikayelyan and N. Sedrakyan},
     title = {On {Periodicity} of {Sums} of {Periodic} {Functions}},
     journal = {Matemati\v{c}eskoe obrazovanie},
     pages = {29--33},
     year = {2000},
     number = {2},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MO_2000_2_a2/}
}