Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh hai » thanh phan, thanh hoa, thanh san
ky lang » ky nang, ky tang, tay lang
ky dang » ky nang, ky danh
hieu ve » hieu van
hieu va » lieu va, hieu qua
duc ban » duc tan, duc van, dua ban
hai cua » thai cua, dai cua, hoi cua
su cac » tu cac, su cao, su can
cua te » cua tu

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

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