Perhaps you should try some spelling variations:
nhan tai » hang tai, van tai, toan tai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
han tai » hang tai, van tai, toan tai
xuc ban » duc ban, cuc ban, quoc ban
cac xuc » cam xuc, cac nuoc, chat xuc
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
co dai » co dan, do dai
co hai » co hoi, o hai, so hai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang ((co hai) OR (co dai)). hieu ve cac xuc ban ((han tai) or (nhan tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((co hai) OR (co dai)). hieu ve cac xuc ban ((han tai) OR (nhan tai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((co hai) OR (co dai)). hieu ve cac xuc ban ((han tai) or (nhan tai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((co hai) OR (co dai)). hieu ve cac xuc ban ((han tai) or (nhan tai)) cua tre*.