Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
te sach » toc sach
hanh di » hanh vi, hanh de, hang di
va tham » van tham, va cham, va thanh
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
hoc anh » hoc nganh, hoc nhanh, ngoc anh
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) OR (hoc anh)) ((ty nang) OR (ty hang)) x ho. hieu va tham thuc van hanh di cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (hoc anh)) ((ty nang) OR (ty hang)) x ho. hieu va tham thuc van hanh di cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (hoc anh)) ((ty nang) OR (ty hang)) x ho. hieu va tham thuc van hanh di cua tre*.