Recent publications have drawn attention to various forms of the electronic book. Intelligent electronic books and superbooks have been discussed. We intend to increment this set with another concept as we are convinced that electronic study books could imply a useful contribution to this emerging set of learning media. Several paradigms have been mentioned to describe the nature of electronic books, such as hypermedia and reactive media. Describing electronic study books makes it necessary to consider some other paradigms as well, such as annotation, information sequencing, and book distribution. Implications of these paradigms for the architecture of future electronic study books are discussed. Finally we outline the concept of an electronic study book platform, being a networked environment for the use of electronic study books.