Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, hieu manh
thanh tung » thanh cong
cong quang » luong quang, thong quang, duong quang
quang than » quang thanh, quang thang, quang tuan
tong cong » trong cong, cong cong, dung cong
doc hieu » toc thieu, hoc thieu, hoc hien
cua tong » cua cong, cua dong, cua nong
than cap » khan cap, thanh lap, thanh cac

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 nganh - ((thanh trung) or (thanh tung)) cua tong cong quang than cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu nganh - ((thanh trung) OR (thanh tung)) cua tong cong quang than cap.
• Adding a wildcard symbol may retrieve word variants: doc hieu nganh - ((thanh trung) or (thanh tung)) cua tong cong quang than cap*.