@article{VMUMM_2015_1_a11,
     author = {D. A. Fedoseev},
     title = {Bifurcation diagrams of natural {Hamiltonian} systems on {Bertrand} manifolds},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {62--65},
     year = {2015},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2015_1_a11/}
}