Perhaps you should try some spelling variations:
cam thuc » am thuc, nam thuc, cam thu
hanh tai » thanh tai, hang tai, han tai
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
te sac » te sach, te san
te cac » tu cac, te cao, de cac
ve cac » va cac, vien cac
va cam » va cham, va cac, va cao

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 sac) OR (((te cac) OR (ve cac)))) ky nang x ho. hieu va cam thuc va hanh tai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sac) or (((te cac) OR (ve cac)))) ky nang x ho. hieu va cam thuc va hanh tai cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((te sac) or (((te cac) OR (ve cac)))) ky nang x ho. hieu va cam thuc va hanh tai cua tre*.