Perhaps you should try some spelling variations:
trung tuan » trung thanh, trung tam, tran tuan
hieu ngan » hieu nganh, hiem ngan, hieu nguon
trung cap » truong cao, trung tam
tong cong » trong cong, cong cong, dung cong
cong dang » cong dong, cong dan, cong dung
doc hieu » toc thieu, hoc thieu, hoc hien
dang van » hoang van, hang va
van bac » van ban, van bao, van hac

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 ngan - thanh ((trung tuan) or (trung cap)) tong cong dang van bac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu ngan - thanh ((trung tuan) OR (trung cap)) tong cong dang van bac*.