Perhaps you should try some spelling variations:
doi chieu » doc hieu, doi chi, mot chieu
cong thuc » cong tac
thuc nang » chuc nang, thuc trang, thich nang
nang cong » nang song, dang cong, bang cong
cong lang » cong vang, cong luong, cong quang
lang phan » nang phan, lang thang, lang phong
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 nang cong lang phan dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (toc thieu)) sach - thanh cong thuc nang cong lang phan dau.
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (toc thieu)) sach - thanh cong thuc nang cong lang phan dau*.