Singular Ordinary Differential Operators and Pseudodifferential Equations Fuchsian differential operators with one singular point Lieear ordinary differential operators with one singular point Linear ordinary differential operators with several singular points Elliptic differential operators in n degenerating at one point Degenerate pseudodifferential operators on a closed curve A finite element method for pseudodifferential equations on a closed curve Appendix. Suboptimal convergence of the Galerkin method with splines for elliptic pseudodifferential equations.