@article{MZM_2006_80_3_a3,
     author = {I. V. Belyakov},
     title = {Extremal {Properties} of {Certain} {Trigonometric} {Functions} and {Chebyshev} {Polynomials}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {350--355},
     publisher = {mathdoc},
     volume = {80},
     number = {3},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2006_80_3_a3/}
}