Perhaps you should try some spelling variations:
quoc ban » quoc bao, quoc lan, quoc quan
su sach » so sach, vu sach
cua tre » cua te, cua triet, dua tren
cuc ban » cua ban, cac ban, cuu ban
cuu tre » cau tren, cau treo
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
y nang » ky nang, ly nang, v nang
ve cac » va cac, vien cac
anh vi » hanh vi, anh va, anh ve

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang xa hoi. hieu ve cac ((quoc ban) or (cuc ban)) anh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang xa hoi. hieu ve cac ((quoc ban) OR (cuc ban)) anh vi ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: su sach y nang xa hoi. hieu ve cac ((quoc ban) or (cuc ban)) anh vi ((cua tre) or (cuu tre))*.