Perhaps you should try some spelling variations:
thieu sang » chieu sang, thieu khang, thieu quang
nhung cong » dung cong, thong cong, hang cong
hoc thieu » toc thieu, hoc hien
trinh vet » trinh viet, trinh vat, trinh ven
trinh ve » trinh he, trinh va, trinh vi
cong san » cong tac
san than » sang than, san thanh, ban than
than cao » toan cao, thai cao, than cap

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: hoc thieu sang - hanh ((trinh ve) OR (trinh vet)) nhung cong san than cao~.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - hanh ((trinh ve) or (trinh vet)) nhung cong san than cao*.