Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
dung cong » dung trong
hoc hieu » hoc thieu, hoc hien, doc hieu
anh bang » anh hoang, anh quang, tinh bang
bang ung » dang ung, bang chung, bang suong
dan than » ban than, van than, dan toan
dan chan » dan gian, dan ca, van chat

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu lang - anh bang ung dung cong ((dan than) or (dan chan)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - anh bang ung dung cong ((dan than) OR (dan chan)) ban.
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - anh bang ung dung cong ((dan than) or (dan chan)) ban*.