Further Reading on Modular Documentation
From Joomla! Documentation
Kurt Ament, Single Sourcing: Building Modular Documentation (2003) William Andrew Publishing, New York, ISBN 0-8155-1491-3. You don't need to buy this book as everything you need to know will be documented on the wiki, but if you are interested in knowing more about single-sourcing and modular documentation then this is the book to read.