Perhaps you should try some spelling variations:
thanh van » thanh san, thanh toan, thanh phan
thanh vai » thanh hai, thanh tai, thanh oai
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
cua tre » cua te, cuu tre, cua triet
cao duc » dao duc, cao suc, giao duc
cam duc » cam xuc, pham duc, nam duoc
nang xa » nang x, lang xa, nang ma
y nang » ky nang, ly nang, v nang

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 xa hoi. hieu van ((cam duc) OR (cao duc)) tan ((thanh vai) or (thanh van)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang xa hoi. hieu van ((cam duc) OR (cao duc)) tan ((thanh vai) OR (thanh van)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang xa hoi. hieu van ((cam duc) OR (cao duc)) tan ((thanh vai) or (thanh van)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang xa hoi. hieu van ((cam duc) OR (cao duc)) tan ((thanh vai) or (thanh van)) cua tre*.