Perhaps you should try some spelling variations:
trinh qua » trinh quan, trinh quang, trinh luat
trinh cua » tinh cua, trinh luat, trinh quan
dung cong » dung trong
doc hieu » hoc thieu, hoc hien
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » 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: ((doc hieu) or (toc thieu)) xanh - hanh ((trinh qua) OR (trinh cua)) dung cong tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (toc thieu)) xanh - hanh ((trinh qua) OR (trinh cua)) dung cong tac toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) or (toc thieu)) xanh - hanh ((trinh qua) OR (trinh cua)) dung cong tac toan cau".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (toc thieu)) xanh - hanh ((trinh qua) OR (trinh cua)) dung cong tac toan cau*.