Perhaps you should try some spelling variations:
doi chieu » doc hieu, doi chi, mot chieu
cong thuc » cong tac
thuc cong » thuoc cong, thu cong, chuc cong
cong cong » cong dong, trong cong, dung cong
cong vang » cong lang, cong quang, cong ngang
vang phan » van phan, nang phan, quang phan
phan dau » phan tu, hang dau

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) or (toc thieu)) sach - thanh cong thuc cong cong vang phan dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (toc thieu)) sach - thanh cong thuc cong cong vang phan dau.
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (toc thieu)) sach - thanh cong thuc cong cong vang phan dau*.