Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » thien van, lieu va, hieu ve
hanh va » hang va, hanh vi
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
luc va » duc va, tuc va
loc va » hoc va
va cua » va chua, via cua, ca cua

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