Perhaps you should try some spelling variations:
thanh van » thanh san, thanh toan, thanh phan
thanh va » hanh va, thanh ha, thanh ve
tu sach » thu sach, su sach, te sach
cao duc » dao duc, cao suc, giao duc
sach ky » sac ky, sach y, sach ty
cac duc » cac du, cac dac, cac nuoc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, x ho

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

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