This collection, in three volumes, presents the scientific achievements of Roderick S C Wong, spanning 45 years of his career. It provides a comprehensive overview of the author's work which includes significant discoveries and pioneering contributions, such as his deep analysis on asymptotic approximations of integrals and uniform asymptotic expansions of orthogonal polynomials and special functions; his important contributions to perturbation methods for ordinary differential equations and difference equations; and his advocation of the Riemann-Hilbert approach for global asymptotics of orthogonal polynomials.The book is an essential source of reference for mathematicians, statisticians, engineers, and physicists. It is also a suitable reading for graduate students and interested senior year undergraduate students.