Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
van thanh » ban thanh, van tuan
ky lang » ky nang, ky tang, tay lang
ky dang » ky nang, ky danh
cac duc » cac du, cac dac, cac nuoc
cao duc » dao duc, cao suc, giao duc
tu san » thu san, tu ban, tu can

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