Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
thanh tung » thanh cong
tung quang » tuong quang, dung quang, hung quang
quang dung » quang trung, ung dung, cuong dung
hieu lang » chieu sang, hieu quang, nhieu tang
cong ban » cong bang, cong tan, cong dan
cong san » cong tac
phan cau » phan dau, phan cac, phan tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hieu lang) or (chieu sach)) - thanh tung quang dung ((cong ban) OR (cong san)) phan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu lang) OR (chieu sach)) - thanh tung quang dung ((cong ban) OR (cong san)) phan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu lang) or (chieu sach)) - thanh tung quang dung ((cong ban) OR (cong san)) phan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu lang) or (chieu sach)) - thanh tung quang dung ((cong ban) OR (cong san)) phan cau*.