Perhaps you should try some spelling variations:
cong thanh » dong thanh, cong trinh, cong tan
hieu tach » chiet tach, chieu sach, lieu thach
hieu cach » hieu cac, chieu sach, hieu ca
tranh cua » doanh cua, manh cua
cua nhung » va nhung
cong manh » cong danh, duong manh, hoang manh
toan ban » van ban

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

• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu tach) OR (hieu cach)) - canh tranh cua nhung ((cong manh) OR (cong thanh)) toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu tach) OR (hieu cach)) - canh tranh cua nhung ((cong manh) or (cong thanh)) toan ban~".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu tach) OR (hieu cach)) - canh tranh cua nhung ((cong manh) or (cong thanh)) toan ban*.