Perhaps you should try some spelling variations:
thanh trong » thanh trung, tranh trong, hanh trong
thieu sang » chieu sang, thieu khang, thieu quang
hoc thieu » toc thieu, hoc hien
trong san » trong cac, cong san, dong san
dung cong » dung trong
san dung » van dung, dan dung, tan dung
cong tac » cong ty
toan cao » toan ban, toan tap

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 - thanh trong san dung cong tac ((toan cao) or (van ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sang - thanh trong san dung cong tac ((toan cao) OR (van ban)).
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - thanh trong san dung cong tac ((toan cao) or (van ban))*.