Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
te sach » toc sach
sach tu » sach thu, cach tu, sach ty
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va
tu nang » tru nang, tu nong, tu nano
ma hoi » mai hoi, ma hoa, me hoi
di cua » dai cua, doi cua, de cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tu nang ((ma hoi) OR (xa hoi)). ((hieu va) OR (hieu qua)) cam thuc va hanh di cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach tu nang ((ma hoi) OR (xa hoi)). ((hieu va) or (hieu qua)) cam thuc va hanh di cua tre~".
• Adding a wildcard symbol may retrieve word variants: te sach tu nang ((ma hoi) OR (xa hoi)). ((hieu va) or (hieu qua)) cam thuc va hanh di cua tre*.