Perhaps you should try some spelling variations:
manh trung » manh tung, thanh trung, manh hung
hieu lang » chieu sang, hieu quang, nhieu tang
hoc hieu » hoc thieu, hoc hien, doc hieu
trung va » truong va, trang va, trung ha
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
toan cau » toan cao, toan tap, toan tai
toan ban » van ban
va dung » van dung, va duong, vat dung

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

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