Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thanh ve » hanh ve, thanh va, thanh vien
hieu van » hieu va, thien van, lieu va
thanh le » thinh le, thanh de, thanh liem
cao duc » dao duc, cao suc, giao duc
cam duc » cam xuc, pham duc, nam duoc
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
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: toc sach y nang xa hoi. hieu van ((cam duc) OR (cao duc)) van ((thanh le) or (thanh ve)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang xa hoi. hieu van ((cam duc) OR (cao duc)) van ((thanh le) OR (thanh ve)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang xa hoi. hieu van ((cam duc) OR (cao duc)) van ((thanh le) or (thanh ve)) cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang xa hoi. hieu van ((cam duc) OR (cao duc)) van ((thanh le) or (thanh ve)) cua tre*.