1. Nonlinear eigenvalue problems and group invariance;Browder,1970
2. Relations between the critical points of a real analytic function of n independent variables;Brown;Amer. J. Math.,1930
3. C′-equivalence of functions near isolated critical points;Kuiper,1972
4. Introduction to Differentiable Manifolds;Lang,1962
5. Differentiability and related properties of nonlinear operators: Some aspects of the role of differentials in nonlinear functional analysis;Nashed,1971