Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
tu cach » tu cac
hieu va » lieu va, hieu qua
cau luc » cau truc, cau phuc
luc cua » luc chua, luc nua, tuc cua
cua dan » cua dang, cua ban, ca dan
dan dai » dat dai, can dai, dan dat
cua tre » cua te, cuu tre, cua triet
va cau » van cau, va cac, va dau
x hoi » xa hoi, o hoi, 5 hoi

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: ((tu cach) OR (thu sach)) ky nang ((x hoi) OR (x ho)). hieu va cau luc cua dan dai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (thu sach)) ky nang ((x hoi) OR (x ho)). hieu va cau luc cua dan dai cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (thu sach)) ky nang ((x hoi) OR (x ho)). hieu va cau luc cua dan dai cua tre*.