Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sang » chieu sach, chieu xanh, nhieu tang
duong manh » duong van
hieu lang » hieu quang, nhieu tang, hieu van
trung can » trung cap, trung van, trong can
can trong » cay trong, ban trong, ca trong
cong manh » cong danh, cong thanh, hoang manh
toan ban » van ban

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