Perhaps you should try some spelling variations:
nhanh thai » nhanh thi, nhanh thanh, nhanh thang
hanh thai » hinh thai, hanh tai, anh thai
cua tre » cua te, cuu tre, cua triet
xuc van » duc van, luc van, vuc van
hieu ve » hieu va, hieu van
cac xuc » cam xuc, cac nuoc, chat xuc
tu san » thu san, tu ban, tu can
san ky » sang ky, van ky, dan ky
ve cac » va cac, vien cac
o hai » co hai, so hai, o lai
o hoi » co hoi, o hoc, o hoa

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

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