Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sang » chieu sach, chieu xanh, nhieu tang
dong thanh » truong thanh
hieu lang » hieu quang, nhieu tang, hieu van
trung cam » trung tam, trung cap, trung nam
cam nhung » cam hung, nam nhung, tham nhung
toan tap » toan 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 cam nhung ((cong trinh) or (dong thanh)) toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (hieu lang)) - thanh trung cam nhung ((cong trinh) OR (dong thanh)) toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sang) OR (hieu lang)) - thanh trung cam nhung ((cong trinh) or (dong thanh)) toan tap".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) OR (hieu lang)) - thanh trung cam nhung ((cong trinh) or (dong thanh)) toan tap*.