@article{MZM_1988_44_1_a6,
     author = {V. I. Ivanov},
     title = {Approximation in $L_p$ by means of piecewise-constant functions},
     journal = {Matemati\v{c}eskie zametki},
     pages = {64--79},
     publisher = {mathdoc},
     volume = {44},
     number = {1},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1988_44_1_a6/}
}