@article{VMUMM_2016_1_a5,
     author = {E. A. Kudryavtseva and D. A. Fedoseev},
     title = {The {Bertrand{\textquoteright}s} manifolds with equators},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {40--44},
     publisher = {mathdoc},
     number = {1},
     year = {2016},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2016_1_a5/}
}