Perhaps you should try some spelling variations:
truong thanh » truong trung, truong thpt, truong chung
chieu sach » chinh sach, chiet tach, chieu sang
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
cong van » cong vang, cong san, song van
van tan » van tuan, van ban, van tai
tan tap » toan tap, han tap, tan tat

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((chieu sach) or (hieu lang)) - hanh ((trung thanh) OR (truong thanh)) nhung cong van tan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chieu sach) OR (hieu lang)) - hanh ((trung thanh) OR (truong thanh)) nhung cong van tan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chieu sach) or (hieu lang)) - hanh ((trung thanh) OR (truong thanh)) nhung cong van tan tap".
• Adding a wildcard symbol may retrieve word variants: doi ((chieu sach) or (hieu lang)) - hanh ((trung thanh) OR (truong thanh)) nhung cong van tan tap*.