Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
bach thuc » cach thuc, bach thu, thach 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 hoi » vu khoi, va hoi, vu hai
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 hoi ky nang x hoi. hieu vien bach thuc day ((dang de) or (dung de)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu hoi ky nang x hoi. hieu vien bach thuc day ((dang de) OR (dung de)) cua tre.
• Adding a wildcard symbol may retrieve word variants: vu hoi ky nang x hoi. hieu vien bach thuc day ((dang de) or (dung de)) cua tre*.