@article{VMUMM_2015_1_a13,
     author = {O. A. Zagryadskii},
     title = {Bertrand surfaces with a {pseudo-Riemannian} metric of revolution},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {66--69},
     publisher = {mathdoc},
     number = {1},
     year = {2015},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2015_1_a13/}
}