Therefore , this book is a prototype of what is today called a pocket book .
The Khoffi Alayee was originally written in two parts so that physicians could put each part in one of his boots while he was on traveling by horse .
This book is a prototype of what is today called a pocket book .
The Khoffi Alayee was originally written in two parts so that physicians could put each part in one of his boots while he was on traveling by horse .