Perhaps you should try some spelling variations:
duong xanh » duong van, duong sach, duong minh
duong manh » duong van
viet tach » viet sach, viet tech, viet thanh
tranh cua » doanh cua, manh cua
cua nhung » va nhung
hoi viet » hai viet, oi viet, thai viet
tuan cau » toan cau, tuan cu, thuan cam
quan cau » quang cao, toan cau, quan ha

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoi viet tach - canh tranh cua nhung ((duong xanh) OR (duong manh)) ((tuan cau) or (quan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi viet tach - canh tranh cua nhung ((duong xanh) OR (duong manh)) ((tuan cau) OR (quan cau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoi viet tach - canh tranh cua nhung ((duong xanh) OR (duong manh)) ((tuan cau) or (quan cau))".
• Adding a wildcard symbol may retrieve word variants: hoi viet tach - canh tranh cua nhung ((duong xanh) OR (duong manh)) ((tuan cau) or (quan cau))*.