Perhaps you should try some spelling variations:
cam quoc » cac quoc, cao quoc, nam quoc
quoc ban » quoc bao, quoc lan, quoc quan
hanh de » hanh ve, hanh kem
sach ky » sac ky, sach y, sach ty
so sach » so sanh, bo sach, co sach
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
anh de » anh d, anh ve, anh du
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang ((xa hoi) or (o hoi)). hieu va cam quoc ban ((anh de) or (hanh de)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang ((xa hoi) OR (o hoi)). hieu va cam quoc ban ((anh de) OR (hanh de)) cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach ky nang ((xa hoi) or (o hoi)). hieu va cam quoc ban ((anh de) or (hanh de)) cua tre*.