Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
hieu van » hieu va, thien van, lieu va
te sach » toc sach
duc van » duc va, duc tan, duc manh
hai cua » thai cua, dai cua, hoi cua
bai cua » ban cua, dai cua, bai ca
van bao » van ban, van dao
bao duc » dao duc, bao luc, cao duc
y nang » ky nang, ly nang, v nang
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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