Perhaps you should try some spelling variations:
khanh thai » nhanh thai, khanh thanh, khanh thuan
thai cuu » thai cua, tai cuc, thi cuc
tu sach » thu sach, su sach, te sach
xuc ban » duc ban, cuc ban, quoc ban
vuc van » duc van, luc van, thuc van
hieu ve » hieu va, hieu van
cuu tre » cua tre, cau tren, cau treo
ve cac » va cac, vien cac
y nang » ky nang, ly nang, v nang
co hai » co dai, co hoi, o hai
o hoc » co hoc, mo hoc, so hoc

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 y nang ((o hoc) or (co hai)). hieu ve cac ((xuc ban) or (vuc van)) khanh thai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((o hoc) OR (co hai)). hieu ve cac ((xuc ban) OR (vuc van)) khanh thai cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((o hoc) or (co hai)). hieu ve cac ((xuc ban) or (vuc van)) khanh thai cuu tre*.