Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thanh di » thanh doi, thanh de, thanh do
cua viet » ca viet, hoa viet, cua dieu
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
cac duc » cac du, cac dac, cac nuoc
cao duc » dao duc, cao suc, giao duc
tu san » thu san, tu ban, tu can
san ky » sang ky, van ky, dan ky

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

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