Perhaps you should try some spelling variations:
thien hieu » thien nhien, thien chien, thien hue
hanh trang » thanh trung, canh tranh, hanh trinh
hieu lang » chieu sang, hieu quang, nhieu tang
trang va » tran van, hang va
cong tan » cong san, cong thanh, cong ty
cong tac » cong ty
toan cau » toan cao, toan ban, toan tap
va tong » va thong, va tuong, va trong

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

• Performing a fuzzy search may retrieve terms with similar spellings: thien hieu lang - hanh trang va tong ((cong tan) or (cong tac)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thien hieu lang - hanh trang va tong ((cong tan) OR (cong tac)) toan cau.
• Adding a wildcard symbol may retrieve word variants: thien hieu lang - hanh trang va tong ((cong tan) or (cong tac)) toan cau*.