Perhaps you should try some spelling variations:
hanh trinh » hanh chinh
hieu lang » chieu sang, hieu quang, nhieu tang
cua nhung » va nhung
cong vang » cong lang, cong quang, cong ngang
cong van » cong san, song van, cong tan
toan cau » toan cao, toan ban, toan tap
he hieu » he nhieu, he dieu, de hieu

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

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