@article{DM_1989_1_3_a3,
     author = {A. F. Sidorenko},
     title = {Extremal problems for $k$-colored graphs and unimprovable inequalities for pairs of random elements},
     journal = {Diskretnaya Matematika},
     pages = {47--52},
     year = {1989},
     volume = {1},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_1989_1_3_a3/}
}