@article{PFMT_2021_1_a7,
     author = {X. Yi and S. F. Kamornikov and V. N. Tyutyanov},
     title = {One property of hereditary saturated formations},
     journal = {Problemy fiziki, matematiki i tehniki},
     pages = {50--53},
     publisher = {mathdoc},
     number = {1},
     year = {2021},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/PFMT_2021_1_a7/}
}