Perhaps you should try some spelling variations:
nhanh thai » nhanh thi, nhanh thanh, nhanh thang
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
dinh thi » dinh tri
cac duc » cac du, cao duc, cac dac
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
tu ban » thu ban, te ban
tu sac » tu sach, tu cac, tu san
o lai » o lao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sac) or (tu ban)) ky nang o lai. hieu vien cac duc van ((nhanh thai) or (dinh thi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sac) OR (tu ban)) ky nang o lai. hieu vien cac duc van ((nhanh thai) OR (dinh thi)) cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sac) or (tu ban)) ky nang o lai. hieu vien cac duc van ((nhanh thai) or (dinh thi)) cua tre*.