@article{DAN_1972_203_2_a1,
     author = {I. A. Aleksandrov and A. E. Prokhorov},
     title = {Estimates of the curvature of level lines in the class $\tilde{S}_p$},
     journal = {Doklady Akademii Nauk},
     pages = {267--269},
     publisher = {mathdoc},
     volume = {203},
     number = {2},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1972_203_2_a1/}
}