Perhaps you should try some spelling variations:
theo hieu » theo chieu, theo tieu, thien hieu
hieu lang » chieu sang, hieu quang, nhieu tang
cua nhung » va nhung
dong cua » dung cua, cong cua, huong cua
cong dan » cong san, cong tan, huong dan
cong tac » cong ty
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 hieu lang - hoat dong cua nhung ((cong dan) or (cong tac)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo hieu lang - hoat dong cua nhung ((cong dan) OR (cong tac)) toan cau.
• Adding a wildcard symbol may retrieve word variants: theo hieu lang - hoat dong cua nhung ((cong dan) or (cong tac)) toan cau*.