%0 Journal Article %A V. M. Buchstaber %A A. P. Veselov %T Conway topograph, $\mathrm{PGL}_2(\pmb{\mathbb Z})$-dynamics and two-valued groups %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 2019 %P 387-430 %V 74 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/RM_2019_74_3_a1/ %G en %F RM_2019_74_3_a1