@article{MZM_1971_10_2_a2,
     author = {N. G. Perlova},
     title = {Infinitesimal first- and second-order deformations of ribbed surfaces of revolution, preserving the normal curvature or geodesic torsion of the boundary parallel},
     journal = {Matemati\v{c}eskie zametki},
     pages = {135--144},
     publisher = {mathdoc},
     volume = {10},
     number = {2},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1971_10_2_a2/}
}