I first used this book a long time ago (1988) when the third edition of it just came out, while I just got a chance to write a review on it much much years after that. It was a required graduate textbook at an Ivy League college. It discussed in depth the finite difference technique applied to the parabolic, elliptic, and hyperbolic types of PDEs. The thing that I really like about this book is, besides having not too much details on mathematical derivations, it gives examples on how to do the calculations by hand. Thus when one would like to "translate" all these calculations into a computer program one could easily test the results (or expected results). Of course there are a lot more books out there talking about finite difference technique but they are perhaps 20 bucks or more expensive than this book. The only minus about this book is it was printed in soft cover, even though mine is still in a very good condition after almost 16 years! I recommend this book for those beginners on finite difference method. I am currently using this book for one of my course.