The Semi-global Isometric Imbedding in R3 of Two Dimensional Riemannian Manifolds with Gaussian Curvature Changing Sign Cleanly. J. Part. Diff. Eq. [Internet]. 1993 Jun. 1 [cited 2026 Mar. 4];6(1):62-79. Available from: https://global-sci.com/jpde/article/view/3735