Perhaps you should try some spelling variations:
thanh tung » thanh cong
hanh trang » thanh trung, canh tranh, hanh trinh
hieu lang » chieu sang, hieu quang, nhieu tang
doi hieu » doi chieu, doc hieu, doi hien
cua dung » cua dang, cua dong, qua dung
cong van » cong vang, song van, cong tan
cong san » cong tac
quan cau » quang cao, toan cau, quan ha

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi hieu lang - ((hanh trang) or (thanh tung)) cua dung ((cong van) OR (cong san)) quan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - ((hanh trang) OR (thanh tung)) cua dung ((cong van) OR (cong san)) quan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi hieu lang - ((hanh trang) or (thanh tung)) cua dung ((cong van) OR (cong san)) quan cau".
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - ((hanh trang) or (thanh tung)) cua dung ((cong van) OR (cong san)) quan cau*.