Perhaps you should try some spelling variations:
trinh vietn » trinh dien, trinh bien, tinh viet
theo chieu » ho chieu, theo chu, thi chieu
trinh viet » ninh viet, trinh vat
nhung cong » dung cong, thong cong, hang cong
cong tap » cuong tap, cong tac, cong tan
tap toan » tap doan, tap quan, bai 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: ((theo chieu) OR (theo tieu)) sach - hanh ((trinh viet) or (trinh vietn)) nhung cong tap toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((theo chieu) OR (theo tieu)) sach - hanh ((trinh viet) OR (trinh vietn)) nhung cong tap toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo chieu) OR (theo tieu)) sach - hanh ((trinh viet) or (trinh vietn)) nhung cong tap toan cao".
• Adding a wildcard symbol may retrieve word variants: ((theo chieu) OR (theo tieu)) sach - hanh ((trinh viet) or (trinh vietn)) nhung cong tap toan cao*.