Perhaps you should try some spelling variations:
lam thuoc » nam thuoc, am thuc, cay thuoc
dinh hai » dinh thai, tinh hai, dinh ha
thuoc va » thuc va, thuoc ma, thuong va
su sach » vu sach
hai cua » thai cua, dai cua, hoi cua
va dinh » van dinh, va kinh, va tinh
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
so sach » so sanh, bo sach, co sach
va lam » van lam, va lap
o hoi » co hoi, o hai, o hoa
o hoc » co hoc, mo hoc, so hoc

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: ((su sach) OR (so sach)) ky nang ((o hoi) OR (o hoc)). hieu va lam thuoc va dinh hai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) ky nang ((o hoi) OR (o hoc)). hieu va lam thuoc va dinh hai cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) ky nang ((o hoi) OR (o hoc)). hieu va lam thuoc va dinh hai cua tre*.