Perhaps you should try some spelling variations:
thuc thong » thuc trong, thuc khong, thuy thong
thong dung » thong cong, thong thuong
cong thuc » cong tac
doc hieu » hoc thieu, hoc hien
dung dat » dung va, dung tai
dat than » dat thanh, dan than, dat khanh
than cap » khan cap, thanh lap, thanh cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc hieu) or (toc thieu)) cach - thanh cong thuc thong dung dat than cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (toc thieu)) cach - thanh cong thuc thong dung dat than cap*.