Perhaps you should try some spelling variations:
cong thanh » dong thanh, cong trinh, cong tan
theo hieu » theo chieu, theo tieu, thien hieu
hieu lang » chieu sang, hieu quang, nhieu tang
cong manh » cong danh, duong manh, hoang manh
dung cua » dung luan, dung cho
toan ban » van ban
ban cua » ban quan

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

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