@article{DAN_1963_153_3_a0,
     author = {S. Ya. Al'per},
     title = {On the best mean first-degree approximation of analytic functions on circles},
     journal = {Doklady Akademii Nauk},
     pages = {503--506},
     publisher = {mathdoc},
     volume = {153},
     number = {3},
     year = {1963},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1963_153_3_a0/}
}