Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
hoc sach » hoc sinh, hoc cac, hoc anh
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
hieu va » lieu va, hieu qua
hanh di » hanh vi, hanh de, hang di
va pham » van pham, va phat, va phap
te sach » toc sach
ty nang » ky nang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua
x hoi » o hoi, x ho, 5 hoi

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 sach)) ty nang ((x hoi) OR (xa hoi)). hieu va pham thuc van hanh di cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (hoc sach)) ty nang ((x hoi) OR (xa hoi)). hieu va pham thuc van hanh di cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (hoc sach)) ty nang ((x hoi) OR (xa hoi)). hieu va pham thuc van hanh di cua tre*.