@article{VMUMM_2009_6_a7,
     author = {A. N. Bakhvalov},
     title = {Waterman classes and piecewise monotone approximations},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {46--48},
     publisher = {mathdoc},
     number = {6},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2009_6_a7/}
}