Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sang » chieu sach, chieu xanh, nhieu tang
thong cong » trong cong, tong cong, thong thong
hieu lang » hieu quang, nhieu tang, hieu van
trung cap » truong cao, trung tam
hang nong » thang long, han tong
dan van » dang van, doan van, dao 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)) - thanh trung cap ((thong cong) or (hang nong)) dan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (hieu lang)) - thanh trung cap ((thong cong) OR (hang nong)) dan van ban.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) or (hieu lang)) - thanh trung cap ((thong cong) or (hang nong)) dan van ban*.