Perhaps you should try some spelling variations:
khanh thuan » khanh thuong, thanh tuan, khan than
khanh thai » nhanh thai, khanh thanh, thanh hai
tu sach » thu sach, su sach, te sach
xuc van » duc van, luc van, vuc van
cac xuc » cam xuc, cac nuoc, chat xuc
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cuu tre » cua tre, cau tren, cau treo
ve cac » va cac, vien cac
co dai » co dan, do dai
o hai » co hai, so hai, o lai

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 ((o hai) or (co dai)). hieu ve cac xuc van ((khanh thai) OR (khanh thuan)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((o hai) OR (co dai)). hieu ve cac xuc van ((khanh thai) OR (khanh thuan)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((o hai) or (co dai)). hieu ve cac xuc van ((khanh thai) OR (khanh thuan)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((o hai) or (co dai)). hieu ve cac xuc van ((khanh thai) OR (khanh thuan)) cuu tre*.