Perhaps you should try some spelling variations:
theo chieu » theo tieu, theo chu, thi chieu
hanh tranh » canh tranh, hanh trinh, hanh trang
tranh cua » doanh cua, manh cua
cua nhung » va nhung
don thanh » dong thanh, son thanh, dan thanh
den thanh » de thanh, dinh thanh, dong thanh
ho chieu » hoc thieu, doi chieu, mot chieu
toan tap » toan ban

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((theo chieu) or (ho chieu)) xanh - hanh tranh cua nhung ((don thanh) OR (den thanh)) toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((theo chieu) OR (ho chieu)) xanh - hanh tranh cua nhung ((don thanh) OR (den thanh)) toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo chieu) or (ho chieu)) xanh - hanh tranh cua nhung ((don thanh) OR (den thanh)) toan tap".
• Adding a wildcard symbol may retrieve word variants: ((theo chieu) or (ho chieu)) xanh - hanh tranh cua nhung ((don thanh) OR (den thanh)) toan tap*.