Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
hanh trang » thanh trung, canh tranh, minh trang
hanh trinh » canh tranh, hanh chinh
theo hieu » theo chieu, theo tieu, thien hieu
cua thong » cua thuong, cua khong, cua tong
cong tac » cong ty
chan cau » phan cau, can cau, chinh cau

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

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