1. Topologie and equations functionelles;Leray;Amer. Sci. École Norm. Sup.,1934
2. A generalized Morse Theory;Palais;Bull. Amer. Math. Soc.,1964
3. An application of the generalized degree;Nirenberg,1972
4. On Riemannian structures of prescribed Gauss curvature for compact 2-manifold;Berger;J. Diff. Geom.,1971
5. A nonlinear problem in global differential geometry;Moser,1973