Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cac duc » cac du, cao duc, cac dac
doi cua » dai cua, hoi cua
va dinh » van dinh, va kinh, va tinh
va danh » va dan, va hanh, dia danh
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
ky dang » ky nang, ky danh
ky tang » ky nang, kho tang, ky trong
ve cac » va cac, vien cac

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: thu sach ((ky tang) OR (ky dang)) xa hoi. hieu ve cac duc ((va danh) OR (va dinh)) doi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ky tang) or (ky dang)) xa hoi. hieu ve cac duc ((va danh) OR (va dinh)) doi cua tre~".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ky tang) or (ky dang)) xa hoi. hieu ve cac duc ((va danh) OR (va dinh)) doi cua tre*.