Perhaps you should try some spelling variations:
hoc thieu » toc thieu, hoc hien
hanh tram » hanh tam, hanh trang, thanh tran
dung cong » dung trong
ho chieu » theo chieu, doi chieu, mot chieu
tram van » tran van, tam van, trang van
van dung » van dong, xay dung, tin dung
tac toan » tam toan, hach toan, tich toan
tap toan » tap doan, tap quan, bai toan

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 (hoc thieu)) xanh - hanh tram van dung cong ((tac toan) OR (tap toan)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (hoc thieu)) xanh - hanh tram van dung cong ((tac toan) OR (tap toan)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (hoc thieu)) xanh - hanh tram van dung cong ((tac toan) OR (tap toan)) cao".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (hoc thieu)) xanh - hanh tram van dung cong ((tac toan) OR (tap toan)) cao*.