books.google.it - "This is the second edition of the now definitive text on partial differential equations (PDE). It offers a comprehensive survey of modern techniques in the theoretical study of PDE with particular emphasis on nonlinear equations. Its wide scope and clear exposition make it a great text for a graduate...http://books.google.it/books/about/Partial_differential_equations.html?hl=it&id=Xnu0o_EJrCQC&utm_source=gb-gplus-sharePartial differential equations
