%0 Journal Article %A A. V. Shchepetilov %T Two-body problem on spaces of constant curvature: I.~Dependence of the Hamiltonian on the symmetry group and the reduction of the classical system %J Teoretičeskaâ i matematičeskaâ fizika %D 2000 %P 249-264 %V 124 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/TMF_2000_124_2_a4/ %G ru %F TMF_2000_124_2_a4