%0 Journal Article %A Yu. N. Shteinikov %T On the size of the set of the product of sets of rational numbers %J Čebyševskij sbornik %D 2020 %P 357-363 %V 21 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/CHEB_2020_21_1_a22/ %G ru %F CHEB_2020_21_1_a22