@article{MO_2020_4_a3,
     author = {S. V. Dvoryaninov},
     title = {Two math notes},
     journal = {Matemati\v{c}eskoe obrazovanie},
     pages = {24--30},
     year = {2020},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MO_2020_4_a3/}
}