Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
ndoc hieu » ngoc hieu, duc hieu, nho hieu
hanh hang » thanh hang, hanh han, hanh mang
hang hang » nang hang, cang thang, hung thang
doc hieu » toc thieu, hoc thieu, hoc hien
cong tan » cong tac, cong san, cong thanh
tan toan » tan tran, tap toan, van toan
toan cao » toan ban, toan tap

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) OR (ndoc hieu)) lang - ((hanh hang) OR (hang hang)) va nhung cong tan toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) or (ndoc hieu)) lang - ((hanh hang) OR (hang hang)) va nhung cong tan toan cao~".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (ndoc hieu)) lang - ((hanh hang) OR (hang hang)) va nhung cong tan toan cao*.