Do anyone have a recommendation for a great resource to learn Green's functions from? Preferably a book with a generous amount of examples. I'm thinking something like a solid introduction to applied partial differential equations or the like. Ideally, there would be a lot of illustrations as well. I know people speak warmly about "Partial Differential Equations for Scientists and Engineers" by Stanley J. Farlow (Dover), but it seems a little light on the Green's function side. Would it be better to learn this from an electrodynamics text? My ultimate interest in Green's functions is 1) to get a better understanding of mathematical modeling in general and 2) to better understand its application in QFT (in terms of propagators). Anyone have some sound advice on where to look? Thanks!