Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
nang tai » hang tai, tang tai, sang tai
va thanh » gia thanh, ban thanh, va tinh
hieu voi » hieu moi, lieu voi, hieu loi
dao cua » dai cua, day cua, dan cua
va hanh » van hanh, va danh, ban hanh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hien vi » hien dai
tai hoi » tai khoi, dai hoi, tai hai
cua te » cua tu

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 nang tai hoi. ((hien vi) or (hieu voi)) tham thuc ((va hanh) OR (va thanh)) dao cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang tai hoi. ((hien vi) OR (hieu voi)) tham thuc ((va hanh) OR (va thanh)) dao cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang tai hoi. ((hien vi) or (hieu voi)) tham thuc ((va hanh) OR (va thanh)) dao cua te".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang tai hoi. ((hien vi) or (hieu voi)) tham thuc ((va hanh) OR (va thanh)) dao cua te*.