Perhaps you should try some spelling variations:
chong cong » cong cong, thong cong, cuong cong
luan chong » luan chung, luan cong, luan phong
tang luan » dung luan
doc hieu » toc thieu, hoc thieu
anh tang » anh bang, anh dang, anh nang
cong tac » cong ty
than cau » phan cau, than cap, thanh chau
toan cau » toan cao, toan ban, toan tap

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 (hoc hien)) xanh - anh tang luan chong cong tac ((than cau) or (toan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (hoc hien)) xanh - anh tang luan chong cong tac ((than cau) OR (toan cau)).
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (hoc hien)) xanh - anh tang luan chong cong tac ((than cau) or (toan cau))*.