Perhaps you should try some spelling variations:
duong cong » dung cong, luong cong, duong trong
mot chieu » doi chieu, ho chieu
tranh cua » doanh cua, manh cua
cua duong » cua dong, cua huong, qua duong
doc hieu » toc thieu, hoc thieu, hoc hien
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: ((mot chieu) or (doc hieu)) xanh - canh tranh cua duong cong tap toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((mot chieu) OR (doc hieu)) xanh - canh tranh cua duong cong tap toan cao*.