Perhaps you should try some spelling variations:
hieu xanh » chieu xanh, hieu manh, hieu nganh
hanh tran » hanh trang, thanh tran, hanh tram
van nhung » van nhuong, va nhung, van hung
cuong tap » luong tap, cong tac, luong tai
doc hieu » toc thieu, hoc thieu, hoc hien
tran van » luan van
tong tap » tuong tac, trong tan, cong tac
cong tan » cong tac, cong san, cong thanh
doan dau » doan dieu, phan dau, doan va

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

• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - hanh tran van nhung ((((tong tap) OR (cong tan))) OR (cuong tap)) doan dau~.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - hanh tran van nhung ((((tong tap) or (cong tan))) or (cuong tap)) doan dau*.