@article{MO_2021_100_4_a7,
     author = {S. V. Zharov and L. B. Medvedeva},
     title = {Second order surfaces as local of points in space},
     journal = {Matemati\v{c}eskoe obrazovanie},
     pages = {49--56},
     publisher = {mathdoc},
     volume = {100},
     number = {4},
     year = {2021},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MO_2021_100_4_a7/}
}