Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
hanh dao » lanh dao, thanh dat, thanh dam
nang tai » hang tai, tang tai, sang tai
dao cua » dai cua, day cua, dan cua
va hanh » van hanh, va thanh, va danh
tai hoi » tai khoi, dai hoi, tai hai
hieu vi » hieu voi, hieu va, hien vi
sach ky » sach y, sach ty, sach kem
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
cua te » cua tu
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) or (sac ky)) nang tai hoi. ((hieu vi) OR (hieu ve)) tham thuc va hanh dao cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) nang tai hoi. ((hieu vi) OR (hieu ve)) tham thuc va hanh dao cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sac ky)) nang tai hoi. ((hieu vi) OR (hieu ve)) tham thuc va hanh dao cua te*".