Perhaps you should try some spelling variations:
hanh trang » thanh trung, canh tranh, hanh trinh
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
cua thong » cua thuong, cua khong, suat thong
cua tong » cua cong, cua dong, cua nong
cong san » cong tac
san van » tan van, luan van, tran van

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

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