%0 Journal Article %A A. O. Yulina %T Variational problems in the works of academician O. I. Somov. Brachistochrone and tautochrone %J Čebyševskij sbornik %D 2024 %P 216-227 %V 25 %N 5 %U http://geodesic.mathdoc.fr/item/CHEB_2024_25_5_a13/ %G ru %F CHEB_2024_25_5_a13