@article{PFMT_2021_3_a9,
     author = {V. N. Kniahina},
     title = {Finite groups with subnormal derived subgroups of $B$-groups},
     journal = {Problemy fiziki, matematiki i tehniki},
     pages = {73--75},
     publisher = {mathdoc},
     number = {3},
     year = {2021},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/PFMT_2021_3_a9/}
}