Perhaps you should try some spelling variations:
thanh trong » thanh trung, tranh trong, hanh trong
chieu sang » chieu sach, chieu xanh, hieu lang
doi chieu » doc hieu, doi chi, ho chieu
qua dung » quang dung, qua song, qua cong
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
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: doi chieu sang - thanh trong ((qua dung) or (su dung)) cong tac toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chieu sang - thanh trong ((qua dung) OR (su dung)) cong tac toan cao.
• Adding a wildcard symbol may retrieve word variants: doi chieu sang - thanh trong ((qua dung) or (su dung)) cong tac toan cao*.