Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh dai » hanh tai, hanh dao, vanh dai
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
hieu ve » hieu van
y nang » ky nang, ly nang, v nang
luc va » duc va, tuc va
loc va » hoc va

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 xa hoi. ((hieu ve) or (hieu va)) cau ((luc va) OR (loc va)) hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang xa hoi. ((hieu ve) OR (hieu va)) cau ((luc va) OR (loc va)) hanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y nang xa hoi. ((hieu ve) or (hieu va)) cau ((luc va) OR (loc va)) hanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach y nang xa hoi. ((hieu ve) or (hieu va)) cau ((luc va) OR (loc va)) hanh dai cua tre*.