Perhaps you should try some spelling variations:
thanh trung » thanh tung
cung trong » cong trong, vung trong, duong trong
hieu sang » chieu sang, hieu quang, nhieu tang
hieu lang » chieu sang, hieu quang, nhieu tang
trung cao » truong cao, trung cap, trung co
ban pha » ban phap, ban nha, ban ha
pha cau » phan cau, phap cau, pha cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu sang) or (hieu lang)) - thanh trung cao ((cung trong) OR (dung trong)) ban pha cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu lang)) - thanh trung cao ((cung trong) OR (dung trong)) ban pha cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sang) or (hieu lang)) - thanh trung cao ((cung trong) OR (dung trong)) ban pha cau".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) or (hieu lang)) - thanh trung cao ((cung trong) OR (dung trong)) ban pha cau*.