Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
dung cong » dung trong
cong lang » cong vang, cong luong, cong quang
lang toan » dang toan, lang thang, lang thanh
doi hieu » doi chieu, doc hieu, doi hien
dap dung » ap dung, dan dung, dap ung
toan ban » van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi hieu lang - ((thanh tung) or (thanh cong)) dap dung cong lang toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - ((thanh tung) OR (thanh cong)) dap dung cong lang toan ban*.