Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu quang » thieu quang, hieu quan, hieu qua
trung cua » truong cua, trung tuan, trung cap
dong cong » duong cong, dung cong, dang cong
hieu van » hieu va, thien van, lieu va
cua dong » chua dong, cua cong, cua dang
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cao » toan cao, thai cao, than cap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoi ((hieu van) or (hieu quang)) - thanh trung cua dong cong dan than cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi ((hieu van) OR (hieu quang)) - thanh trung cua dong cong dan than cao.
• Adding a wildcard symbol may retrieve word variants: hoi ((hieu van) or (hieu quang)) - thanh trung cua dong cong dan than cao*.