Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
hanh hai » thanh hai, nhanh hai, hang hai
hai cua » thai cua, dai cua, hoi cua
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh
tu sach » su sach, te sach, tu cach
cua tre » cua te, cuu tre, cua triet
v nang » va nang, vu nang, van nang
luc va » tuc va, loc va
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (tu sach)) v nang x hoi. hieu va tham ((duc va) or (luc va)) hanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) v nang x hoi. hieu va tham ((duc va) OR (luc va)) hanh hai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (tu sach)) v nang x hoi. hieu va tham ((duc va) or (luc va)) hanh hai cua tre*.