Copyright (c) Shih Yuncheng <shirock@educities.edu.tw>.

Rock's saying: http://home.educities.edu.tw/shirock/

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with the Invariant Sections being LIST THEIR TITLES, with the Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST. A copy of the license is included in the section entitled "GNU Free Documentation License".

http://www.fsf.org/licenses/fdl.html