Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
hanh trinh » canh tranh, hanh chinh
hoc thien » hoc hien, hoc thieu, hoc thiet
quan cong » luan cong, quan dong, quan long
qua cong » cua cong, qua song, va cong
cong tac » cong ty
tac tran » tan tran, tac trai, tac tren
tran cau » tran chau, toan cau, ran cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thien hach - hanh trinh ((quan cong) or (qua cong)) cong tac tran cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thien hach - hanh trinh ((quan cong) OR (qua cong)) cong tac tran cau.
• Adding a wildcard symbol may retrieve word variants: hoc thien hach - hanh trinh ((quan cong) or (qua cong)) cong tac tran cau*.