There are a great number of books on instructional design but most of them deal with either the theoretical aspect of the subject or its practical application. (yourelearningworld.com)
You'd have to sell a large number of books in order to hit # 1 in this category. (booklaunchers.com)
It is the first drop in numbers of books sold in this medium for the «big five» since the digital age began. (theguardian.com)