Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
cac thuc » cach thuc, cac thu, can thuc
thuc day » thuc dan, thuc vat
dang de » dang deo, dang do, vang de
dung de » dung he, dung dat
cua tre » cua te, cuu tre, cua triet
vu hai » su hai, vu ha
hai ky » thai ky, hoi ky, hai ly
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu hai ky nang x hoi. hieu vien cac thuc day ((dang de) or (dung de)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu hai ky nang x hoi. hieu vien cac thuc day ((dang de) OR (dung de)) cua tre.
• Adding a wildcard symbol may retrieve word variants: vu hai ky nang x hoi. hieu vien cac thuc day ((dang de) or (dung de)) cua tre*.