@article{IM2_2003_67_4_a0,
     author = {A. S. Belov},
     title = {Some estimates for non-negative trigonometric polynomials and properties of these polynomials},
     journal = {Izvestiya. Mathematics},
     pages = {637--653},
     year = {2003},
     volume = {67},
     number = {4},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2003_67_4_a0/}
}