@article{MZM_1981_29_6_a2,
     author = {V. N. Poroshenko},
     title = {Uniqueness of an algebraic polynomial of best approximation in the~$L_1$ metric},
     journal = {Matemati\v{c}eskie zametki},
     pages = {817--828},
     publisher = {mathdoc},
     volume = {29},
     number = {6},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1981_29_6_a2/}
}