Two-dimensional manifolds of bounded curvature. Part II. Collection of articles on the intrinsic geometry of surfaces, Trudy Mat. Inst. Steklov., 76, ed. A. D. Aleksandrov, V. A. Zalgaller, I. G. Petrovskii, 1965, 152 ñ. http://mi.mathnet.ru/book1128
A. D. Aleksandrov, V. A. Zalgaller, Two-dimensional manifolds of bounded curvature. (Foundations of the intrinsic geometry of surfaces), Trudy Mat. Inst. Steklov., 63, 1962, 264 ñ. http://mi.mathnet.ru/book1119
