Shorthand for BOOK Structure and Interpretation of Computer Programs. This book is one of a small handful commonly referenced when someone asks for a Scheme reference book. Beyond that it is a very good introduction into computational concepts in general. It's also a classic of language theory, quite apparent from its use of Scheme for exposition; in fact, CL hears more recommendations of it as a tutorial on programming principles than for Scheme. For the latter role, the usual candidates are The Little Schemer, ...