books.google.fr - Mathematically self-contained, this text for advanced undergraduates and graduate students combines two important methods -- the finite element method and the variational method -- into the framework of functional analysis. It does so in order to explain potential applications to approximation of nonhomogeneous...https://books.google.fr/books/about/Approximation_of_Elliptic_Boundary_Value.html?hl=fr&id=SlzWFb7_KkcC&utm_source=gb-gplus-shareApproximation of Elliptic Boundary-Value Problems
