I've uploaded some modifications to Pier-Book-EPUB. Let me know if there are any problems. Here's what's changed: (1) stylesheets - any localStyleSheet that is defined in the chain from book/part/chapter, are now included in the zip archive, and linked in the corresponding chapter.html file. Your EPUB book formatting may change, if a stylesheet gets included. (2) The +value:book.contents+ now generates correct links. (3) A major flaw was fixed - previously, extra section/subsection/etc. files were being added to the zip archive. These should not have been present, since the chapter file has all the content. Many testcases are included. Hopefully these will prevent the functionality from changing or regressing without warning.