Perhaps you should try some spelling variations:
theo hieu » theo chieu, theo tieu, thien hieu
hieu lang » chieu sang, hieu quang, nhieu tang
nang van » dang van, tang van, nong van
lang van » dang van, tang van, hoang van
cong tan » cong san, cong thanh, cong ty
cong tac » cong ty
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 hieu lang - anh ((nang van) OR (lang van)) nhung ((cong tan) or (cong tac)) toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo hieu lang - anh ((nang van) OR (lang van)) nhung ((cong tan) OR (cong tac)) toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo hieu lang - anh ((nang van) OR (lang van)) nhung ((cong tan) or (cong tac)) toan tap".
• Adding a wildcard symbol may retrieve word variants: theo hieu lang - anh ((nang van) OR (lang van)) nhung ((cong tan) or (cong tac)) toan tap*.