@article{01780526, title = {On the curvature of nonregular saddle surfaces in the hyperbolic and spherical three-space.}, journal = {Abstract and Applied Analysis}, volume = {7}, year = {2002}, pages = {113-123}, doi = {10.1155/S1085337502000799}, zbl = {1029.53083}, language = {en}, url = {http://dml.mathdoc.fr/item/01780526} }
Kalikakis, Dimitrios E. On the curvature of nonregular saddle surfaces in the hyperbolic and spherical three-space.. Abstract and Applied Analysis, Tome 7 (2002) pp. 113-123. doi : 10.1155/S1085337502000799. http://gdmltest.u-ga.fr/item/01780526/