Perhaps you should try some spelling variations:
trinh thuat » trinh luat, trinh thuc, trinh chat
trinh thiet » trinh viet, trinh thi
thieu tinh » trieu tinh, chieu tinh, thien tinh
hoc thieu » toc thieu, hoc hien
hung cong » nhung cong, hung cuong, phung cong
dan toan » van toan, manh toan, xuan toan
dan than » dan chan, ban than, van than

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 tinh - hanh ((trinh thuat) or (trinh thiet)) hung cong ((dan toan) OR (dan than)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu tinh - hanh ((trinh thuat) OR (trinh thiet)) hung cong ((dan toan) OR (dan than)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu tinh - hanh ((trinh thuat) or (trinh thiet)) hung cong ((dan toan) OR (dan than)) cao".
• Adding a wildcard symbol may retrieve word variants: hoc thieu tinh - hanh ((trinh thuat) or (trinh thiet)) hung cong ((dan toan) OR (dan than)) cao*.