Perhaps you should try some spelling variations:
thanh trong » thanh trung, tranh trong, hanh trong
doi chieu » doi chi, ho chieu, mot chieu
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
cac dung » cach dung, cac duong, tac dung
cong san » cong tac
san van » tan van, luan van, tran van

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doi chieu) or (doc hieu)) xanh - thanh trong cac dung cong san van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (doc hieu)) xanh - thanh trong cac dung cong san van ban.
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (doc hieu)) xanh - thanh trong cac dung cong san van ban*.