books.google.fr - Don't let the title fool you! If you are interested in numerical analysis, applied mathematics, or the solution procedures for differential equations, you will find this book useful. Because of Lanczos' unique style of describing mathematical facts in nonmathematical language, Linear Differential Operators...http://books.google.fr/books/about/Linear_Differential_Operators.html?hl=fr&id=I1UtTmTjJEcC&q=obtain&utm_source=gb-gplus-shareLinear Differential Operators