@article{VMUMM_2011_5_a6,
     author = {D. I. Bugrov},
     title = {Bulgakov problem of the accumulation of perturbations},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {39--43},
     publisher = {mathdoc},
     number = {5},
     year = {2011},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2011_5_a6/}
}