Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
van thanh » van tuan
ky tang » ky dang, kho tang, ky trong
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
su sac » su sach, su cac, su xac
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ((ky tang) or (ky nang)) xa hoi. hieu ve cac duc ((van thanh) OR (ban thanh)) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ((ky tang) OR (ky nang)) xa hoi. hieu ve cac duc ((van thanh) OR (ban thanh)) hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ((ky tang) or (ky nang)) xa hoi. hieu ve cac duc ((van thanh) OR (ban thanh)) hai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sac ((ky tang) or (ky nang)) xa hoi. hieu ve cac duc ((van thanh) OR (ban thanh)) hai cua tre*.