Perhaps you should try some spelling variations:
ban hang » ngan hang
tien cua » trien cua, tiep cua, dien cua
so sanh » do sanh
sanh ky » hanh ky, sang ky, nganh ky
qua cac » cua cac
cac tac » cac toc, cac bac, cac dac
cua tre » cua te, cuu tre, cua triet
x hoi » o hoi, x ho, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sanh ky nang ((x hoi) OR (xa hoi)). hieu qua cac tac ((ban hanh) or (ban hang)) tien cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sanh ky nang ((x hoi) OR (xa hoi)). hieu qua cac tac ((ban hanh) OR (ban hang)) tien cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sanh ky nang ((x hoi) OR (xa hoi)). hieu qua cac tac ((ban hanh) or (ban hang)) tien cua tre".
• Adding a wildcard symbol may retrieve word variants: so sanh ky nang ((x hoi) OR (xa hoi)). hieu qua cac tac ((ban hanh) or (ban hang)) tien cua tre*.