Structure and interpretation of computer programs

This book is not for the average person with a casual interest in computer programming, or for someone who wants to learn Scheme and Scheme only. This book is designed for motivated study, as you would find in a very difficult college course.

I have almost finished reading this book. it is difficult, isn't it ?

Computer programmers who read this book come out changed, for the better. I've been Programming mostly in imperative languages (C C++ Java) for 10 years and have just received a Masters Degree in IT and have recently been making forays into Functional programming.