Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
hanh trinh » canh tranh, hanh chinh
hieu lang » chieu sang, nhieu tang, hieu van
trinh cua » tinh cua, trinh luat, trinh quan
dung cong » dung trong
vang toan » dang toan, quang toan, vang trang
cua dung » cua dang, cua dong, qua dung
van toan » van tuan, van tan, van thanh

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

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