Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hanh hang » thanh hang, hang hang, hanh mang
cua nhung » va nhung
ho chieu » theo chieu, hoc thieu, doi chieu
hanh han » hanh nhan, hanh phan, hanh san
cong tap » cuong tap, cong tac, cong tan
tap toan » tap doan, tap quan, bai 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: ((theo tieu) or (ho chieu)) xanh - ((hanh hang) OR (hanh han)) cua nhung cong tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((theo tieu) OR (ho chieu)) xanh - ((hanh hang) OR (hanh han)) cua nhung cong tap toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo tieu) or (ho chieu)) xanh - ((hanh hang) OR (hanh han)) cua nhung cong tap toan cau".
• Adding a wildcard symbol may retrieve word variants: ((theo tieu) or (ho chieu)) xanh - ((hanh hang) OR (hanh han)) cua nhung cong tap toan cau*.