Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
tu sach » thu sach, su sach, te sach
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
ky dang » ky nang, ky danh
ky tang » ky nang, kho tang, ky trong
tuc va » thuc va, truc va, duc va
va cam » va cham, va cac, va cao

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 sach ((ky tang) OR (ky dang)) xa hoi. hieu va cam ((tuc va) OR (tuc xa)) hanh tai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky tang) or (ky dang)) xa hoi. hieu va cam ((tuc va) OR (tuc xa)) hanh tai cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky tang) or (ky dang)) xa hoi. hieu va cam ((tuc va) OR (tuc xa)) hanh tai cua tre*.