@article{DM_2001_13_3_a9,
     author = {V. S. Monakhov and O. A. Shpyrko},
     title = {On the nilpotent $\pi$-length of a finite $\pi$-solvable group},
     journal = {Diskretnaya Matematika},
     pages = {145--152},
     publisher = {mathdoc},
     volume = {13},
     number = {3},
     year = {2001},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_2001_13_3_a9/}
}