@article{VMUMM_2012_6_a5,
     author = {A. Zh. Ydyrys},
     title = {Double trigonometric series with lacunary constant sign coefficients},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {33--35},
     year = {2012},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2012_6_a5/}
}