Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
vu sach » vu bach, su sach, vu khach
nang xa » nang x, lang xa, nang ma
duc van » duc va, duc manh, duc phan
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
vi cua » vai cua, di cua

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 y nang xa hoi. hieu vien cac ((((duc tan) or (cua ban))) or (duc van)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach y nang xa hoi. hieu vien cac ((((duc tan) OR (cua ban))) OR (duc van)) hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: vu sach y nang xa hoi. hieu vien cac ((((duc tan) or (cua ban))) or (duc van)) hanh vi cua tre*.