Harmonic analysis on Euclidean spaces 3 Approximation theory 2 Approximations and expansions 2 Functional analysis 2 Functions of a complex variable 2 Functions of complex variables 2 Number theory 2 Operator theory 2 Probability theory and stochastic processes 2 Real functions 2 Abstract harmonic analysis -- Instructional exposition (textbooks, tutorial papers, etc.) 1 Fourier transformations 1 Functional analysis -- Instructional exposition (textbooks, tutorial papers, etc.) 1 Harmonic analysis 1 Harmonic analysis on Euclidean spaces -- Instructional exposition (textbooks, tutorial papers, etc.) 1 Instructional exposition (textbooks, tutorial papers, etc.) 1 Linear and multilinear algebra; matrix theory -- Instructional exposition (textbooks, tutorial papers, etc.) 1 Mathematical analysis 1 Measure and integration -- Instructional exposition (textbooks, tutorial papers, etc.) 1 Real functions -- Instructional exposition (textbooks, tutorial papers, etc.) 1 Topological groups, Lie groups -- Locally compact abelian groups (LCA groups) -- General properties and structure of LCA groups 1