@article{SM_2008_199_5_a2,
     author = {I. V. Mykytyuk and A. M. Stepin},
     title = {A sufficient condition for reduction by stages: proof and applications},
     journal = {Sbornik. Mathematics},
     pages = {663--671},
     publisher = {mathdoc},
     volume = {199},
     number = {5},
     year = {2008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2008_199_5_a2/}
}