Perhaps you should try some spelling variations:
trinh thiet » trinh viet, trinh thi
trinh thuat » trinh luat, trinh thuc, trinh chat
phung cong » nhung cong, phong cong, nhung chong
doi chieu » doc hieu, doi chi, mot chieu
ho chieu » theo chieu, hoc thieu, mot chieu
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh 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: ((ho chieu) OR (doi chieu)) tinh - hanh ((trinh thuat) or (trinh thiet)) phung cong dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (doi chieu)) tinh - hanh ((trinh thuat) OR (trinh thiet)) phung cong dan toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) OR (doi chieu)) tinh - hanh ((trinh thuat) or (trinh thiet)) phung cong dan toan cao".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) OR (doi chieu)) tinh - hanh ((trinh thuat) or (trinh thiet)) phung cong dan toan cao*.