Perhaps you should try some spelling variations:
dang cong » dung cong
doc hieu » hoc thieu, hoc hien
nhan dat » nhan dan, nhan vat, nhan dai
dat dang » da dang, dat hang, dai dang
cong tan » cong tac, cong san, cong thanh
tan van » tran van, tang van, luan van
van dan » van ban, ban dan, van dao

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) or (toc thieu)) tinh - nhan dat dang cong tan van dan ca~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (toc thieu)) tinh - nhan dat dang cong tan van dan ca.
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (toc thieu)) tinh - nhan dat dang cong tan van dan ca*.