Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh hai » thanh hai, nhanh hai, hang hai
hieu va » lieu va, hieu qua
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
nang ma » tang ma, sang ma, nang cao
y nang » ky nang, ly nang, v nang
luc va » duc va, tuc va
loc va » hoc va
ma hoi » mai hoi, xa hoi, ma hoa

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 y nang ma hoi. ((hieu ve) or (hieu va)) cau ((luc va) or (loc va)) hanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang ma hoi. ((hieu ve) OR (hieu va)) cau ((luc va) OR (loc va)) hanh hai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach y nang ma hoi. ((hieu ve) or (hieu va)) cau ((luc va) or (loc va)) hanh hai cua tre*.