In his emphasis on textbook, Aggarwal
(2001) alluded to the comment of UNESCO (1970) publication in Preparing Textbook
Manuscripts: A Guide for Authors in Developing Countries by reporting that classroom
teaching activities depend heavily on the textbook especially in the institutions where the
teachers are not well qualified. On the same issue, he reported Altbach (1983) by saying that
textbooks are central to schooling and has never been replaced in educational processes.