Finally I started to write a code to create EPUB myself. It's not too complicated but is bothered. I swear people who say that EPUB could be a master format for every books will regret. I'm still in doubt that HTML becomes a central format for every books. At least, it will take years and years finding the most efficient and sustainable way of creating books in digital media. Chances are that then books themselves are getting really old-fashioned and all the information are going to be spread through the Web. It's not a matter of me though. What concerns me now is arranging the stuff in one's mind in a tree form and representing it as a book form.