Perhaps you should try some spelling variations:
thanh dung » thanh duong, thanh tung, thanh hung
dung luong » dung thuong, dung phuong, dung truong
luong cong » dung cong, trong cong, cong cong
hieu tinh » chieu tinh, lieu tinh, kieu tinh
luong bac » luong cac, phuong bac, luong va
duong van » duong va, luong va, dang van
doc hieu » toc thieu, hoc thieu, hoc hien
khan cap » khan ap, than cap, khoan cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu tinh - thanh dung luong cong ((luong bac) or (duong van)) khan cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu tinh - thanh dung luong cong ((luong bac) OR (duong van)) khan cap.
• Adding a wildcard symbol may retrieve word variants: doc hieu tinh - thanh dung luong cong ((luong bac) or (duong van)) khan cap*.