@article{MZM_1991_49_1_a1,
     author = {\`E. S. Belinskii},
     title = {Two extremal problems for trigonometric polynomials with a prescribed number of harmonics},
     journal = {Matemati\v{c}eskie zametki},
     pages = {12--18},
     publisher = {mathdoc},
     volume = {49},
     number = {1},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1991_49_1_a1/}
}