Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
thanh vai » thanh van, thanh tai, thanh oai
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
cao duc » dao duc, cao suc, giao duc
cam duc » cam xuc, pham duc, nam duoc
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
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 y nang x hoi. hieu van ((cam duc) OR (cao duc)) van ((thanh vai) or (thanh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang x hoi. hieu van ((cam duc) OR (cao duc)) van ((thanh vai) OR (thanh hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang x hoi. hieu van ((cam duc) OR (cao duc)) van ((thanh vai) or (thanh hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang x hoi. hieu van ((cam duc) OR (cao duc)) van ((thanh vai) or (thanh hai)) cua tre*.