Perhaps you should try some spelling variations:
thieu quang » hieu quang, thien quan, trien quang
thieu sang » chieu sang, thieu khang, hieu lang
dang cong » dung cong
tranh va » tranh van, trang va, trinh va
cong tac » cong ty
tac pham » thuc pham, san pham
pham dau » phan dau, pham dac, pham dat
va dang » van dang, va nang, va lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thieu sang) or (thieu quang)) - canh tranh va dang cong tac pham dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (thieu quang)) - canh tranh va dang cong tac pham dau.
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (thieu quang)) - canh tranh va dang cong tac pham dau*.