@article{AA_1991_3_5_a4,
     author = {A. M. Minkin},
     title = {The reflection of indices and unconditional bases of exponentials},
     journal = {Algebra i analiz},
     pages = {109--134},
     publisher = {mathdoc},
     volume = {3},
     number = {5},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AA_1991_3_5_a4/}
}