@article{SEMR_2015_12_a66,
     author = {D. I. Boytsov and S. P. Sidorov},
     title = {Linear approximation method preserving $k$-monotonicity},
     journal = {Sibirskie \`elektronnye matemati\v{c}eskie izvesti\^a},
     pages = {21--27},
     publisher = {mathdoc},
     volume = {12},
     year = {2015},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SEMR_2015_12_a66/}
}