@article{MO_2021_100_4_a5,
     author = {V. I. Voytitsky},
     title = {Gifts from {Santa} {Claus} or variations on the themes of the classics},
     journal = {Matemati\v{c}eskoe obrazovanie},
     pages = {28--37},
     publisher = {mathdoc},
     volume = {100},
     number = {4},
     year = {2021},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MO_2021_100_4_a5/}
}