Perhaps you should try some spelling variations:
hanh thai » nhanh thai, hanh tai, anh thai
hinh thai » sinh thai, tinh thai, dinh thi
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
cac duc » cac du, cac dac, cac nuoc
cao duc » dao duc, cao suc, giao duc
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
nang o » nang co, nang ho, nang ro
o lai » o lao

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 sac ky nang o lai. hieu van ((cac duc) OR (cao duc)) van ((hanh thai) OR (hinh thai)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang o lai. hieu van ((cac duc) or (cao duc)) van ((hanh thai) OR (hinh thai)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang o lai. hieu van ((cac duc) or (cao duc)) van ((hanh thai) OR (hinh thai)) cua tre*.