Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
thanh tai » thanh toan, doanh tai, thanh san
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
cuu tre » cua tre, cau tren, cau treo
cao duc » dao duc, cao suc, giao duc
cam duc » cam xuc, pham duc, nam duoc
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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 o hoi. hieu van ((cam duc) or (cao duc)) van ((thanh tai) or (thanh hai)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang o hoi. hieu van ((cam duc) OR (cao duc)) van ((thanh tai) OR (thanh hai)) cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang o hoi. hieu van ((cam duc) or (cao duc)) van ((thanh tai) or (thanh hai)) cuu tre*.