Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cay » vien cac, vien cao, vien xay
cay thuc » cay thuoc, can thuc, day thuc
thuc dan » thuc hanh, hoc dan, thuc vat
dan hanh » dang hanh, dan khanh, dan thanh
vu sach » vu bach, su sach, vu khach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
nang xa » nang x, lang xa, nang ma
cua tre » cuu tre, cua triet, dua tren
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach tu nang xa hoi. hieu vien cay thuc dan hanh vi ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach tu nang xa hoi. hieu vien cay thuc dan hanh vi ((cua tre) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: vu sach tu nang xa hoi. hieu vien cay thuc dan hanh vi ((cua tre) or (cua te))*.