TY - BOOK ED - Reshetnyak, Yu G TI - Geometry IV : non-regular Riemannian geometry T2 - Encyclopaedia of mathematical sciences. no. 72 SN - 3540547010 U1 - 515.373 PY - 1993/// CY - Berlin PB - Springer-Verlag KW - Geometry,Riemannian KW -