Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
chieu tinh » trieu tinh, lieu tinh, chau tinh
hoang van » hang va
dang cong » dung cong
cong thuc » cong tac
lua dang » cua dang, lua sang, luan nang
pham phi » pham thi, pham chi, pham phap
van lua » van luan, van lu, van luc

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 (chieu tinh)) - hoang van lua dang cong thuc pham phi~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chieu sach) OR (chieu tinh)) - hoang van lua dang cong thuc pham phi.
• Adding a wildcard symbol may retrieve word variants: doi ((chieu sach) or (chieu tinh)) - hoang van lua dang cong thuc pham phi*.