Reduction methods via minimax -- On multiple solutions of nonlinear elliptic equations with odd nonlinearities -- Positive solutions of semilinear elliptic problems -- A regularity theorem for inverse bounded and accretive operators in abstract Hilbert space -- How to remember the Sobolev inequalities -- The adjoint equation of a linear Volterra Stieltjes-integral equation with a linear constraint -- On a fixed point index method for the analysis of the asymptotic behavior and boundary value problems of process and semidynamical systems -- to bifurcation theory -- Sobre estabilidad topologica -- Solvability of operator equations involving nonlinear perturbations of Fredholm mappings of nonnegative index and applications -- Some remarks on a wave equation with a nonlocal interaction -- The mountain pass theorem: Theme and variations -- Optimal spline solutions of systems of ordinary differential equations -- Structurally stable second order differential equations

1. Mathematics
2. Mathematical analysis
3. Analysis (Mathematics)
4. Mathematics
5. Analysis