Functional analysis 116 Theory of distributions (Functional analysis) 17 Congresses 14 Approximation theory 9 Numerical analysis 6 Mathematical optimization 5 Fourier transformations 4 Linear topological spaces 4 Nonlinear functional analysis 4 Numerical solutions 4 Analytic functions 3 Calculus 3 Calculus, Operational 3 Differential equations 3 Differential equations, Partial 3 Equations 3 Functions 3 Functions of real variables 3 Hilbert space 3 Mathematical analysis 3 Operator theory 3 System analysis 3 Algebras, Linear 2 Banach spaces 2 Boundary value problems 2 Calculus of operations 2 Control theory 2 Differential equations, Linear 2 Fourier analysis 2 Function spaces 2