Perhaps you should try some spelling variations:
trinh vietn » trinh dien, trinh bien, tinh viet
theo chieu » theo tieu, ho chieu, theo chu
chieu sang » chieu sach, chieu xanh, hieu lang
trinh viet » ninh viet, trinh vat
nhung cong » dung cong, thong cong, hang cong
tap toan » tap doan, bai toan
tap quan » tac quan, hai quan

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo chieu sang - hanh ((trinh viet) or (trinh vietn)) nhung cong ((tap toan) or (tap quan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chieu sang - hanh ((trinh viet) OR (trinh vietn)) nhung cong ((tap toan) OR (tap quan)) cao.
• Adding a wildcard symbol may retrieve word variants: theo chieu sang - hanh ((trinh viet) or (trinh vietn)) nhung cong ((tap toan) or (tap quan)) cao*.