Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu lang » chieu sang, hieu quang, nhieu tang
trung nam » trung tam, trong nam, trung cap
cong danh » cuong danh, cong thanh, cong khanh
hoc hieu » hoc thieu, hoc hien, doc hieu
nam dung » nam vung, nam dong, am dung
cong dan » cong san, cong tan, huong dan

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 - thanh trung nam dung ((cong danh) OR (cong dan)) ((toan ban) or (van ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - thanh trung nam dung ((cong danh) OR (cong dan)) ((toan ban) OR (van ban)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu lang - thanh trung nam dung ((cong danh) OR (cong dan)) ((toan ban) or (van ban))".
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - thanh trung nam dung ((cong danh) OR (cong dan)) ((toan ban) or (van ban))*.