Perhaps you should try some spelling variations:
thanh thong » thanh thuong, thanh thang, thanh chuong
hanh trung » thanh trung, hanh trang, manh trung
chieu sang » chieu sach, chieu xanh, nhieu tang
thanh hong » thanh huong, thanh hoang, thanh cong
hieu lang » hieu quang, nhieu tang, hieu van
ban thanh » ban hanh, ban hang
cong ban » cong bang, cong san, cong tan

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