參考資料

1) http://hk.knowledge.yahoo.com/question/question?qid=7010012701406

2) http://www.myconan852.scicube.info/hksfad/project/content/4.htm

3) http://hk.knowledge.yahoo.com/question/question?qid=7010020401405

4) http://hk.knowledge.yahoo.com/question/question?qid=7007032402609

5) http://hk.knowledge.yahoo.com/question/question?qid=7007122903670

6) http://hk.knowledge.yahoo.com/question/question?qid=7008021900885