Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
thanh va » thanh van, hanh va, thanh ha
ban duc » ban duoc, van duc, ban dac
duc van » duc va, duc tan, duc manh
cuu tre » cua tre, cau tren, cau treo
nang o » nang co, nang ho, nang ro
va cuu » va cau, va chu, va huu
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: ((te sach) or (toc sach)) ky nang o hoi. hieu van ban duc van thanh va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang o hoi. hieu van ban duc van thanh va cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky nang o hoi. hieu van ban duc van thanh va cuu tre*.