Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
chieu tinh » trieu tinh, lieu tinh, chau tinh
lang trong » dung trong, cong trong, dong trong
trong van » trong cac
dong cong » duong cong, dung cong, dang cong
cong tan » cong tac, cong san, cong thanh
tan van » tran van, tang van, luan van

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 sach) or (chieu tinh)) - lang trong van dong cong tan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sach) OR (chieu tinh)) - lang trong van dong cong tan van ban.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sach) or (chieu tinh)) - lang trong van dong cong tan van ban*.