Approximations -- expansions-- Mathematics 80 Asymptotic expansions 10 History 7 Dissertations, Academic (Ph.D) 6 Territorial expansion 6 Thesis (Ph.D)-Physics 6 Approximation theory 5 Expansion (Heat) 4 Crystals 3 Differential equations 3 Elasticity 3 Imperialism 3 Operator theory 3 Approximations and expansions 2 Boundary value problems 2 China 2 Colonies 2 Eigenfunction expansions 2 Functional analysis 2 Functions of a complex variable 2 Functions of complex variables 2 Functions, Special 2 Harmonic analysis on Euclidean spaces 2 Land tenure 2 Nationalism 2 Number theory 2 Numerical solutions 2 Postcolonialism 2 Probability theory and stochastic processes 2 Real functions 2