Perhaps you should try some spelling variations:
hieu sang » chieu sang, hieu lang, hieu quang
hanh tang » hanh trang, anh tang, hanh mang
chua nang » chuc nang, chua xang, kha nang
doc hieu » toc thieu, hoc thieu, hoc hien
cua nang » cua dang, cua hang, cua nong
dan toan » van toan, dan than, manh toan
dan chan » dan gian, dan ca, van chat

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - hanh tang ((cua nang) OR (chua nang)) cong ((dan toan) OR (dan chan)) cau~.
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - hanh tang ((cua nang) or (chua nang)) cong ((dan toan) or (dan chan)) cau*.