Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
thuc dan » thuc hanh, hoc dan, thuc vat
dan tinh » doan tinh, dang tinh, dan trinh
tinh dai » trinh dai, tinh da, tinh hai
sach ty » sach y, sach thu, xach tay
sach tu » sach thu, cach tu, sach uu
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet

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: thuoc ((sach ty) OR (sach tu)) lang xa hoi. hieu van pham thuc dan tinh dai cua tre~.
• Adding a wildcard symbol may retrieve word variants: thuoc ((sach ty) or (sach tu)) lang xa hoi. hieu van pham thuc dan tinh dai cua tre*.