Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
san thanh » van thanh, son thanh, dan thanh
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
van bac » van ban, van bao, van hac
bac dac » bac dai, ban dac, bac dan
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang x hoi. hieu van bac dac ((san thanh) OR (ban thanh)) dai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang x hoi. hieu van bac dac ((san thanh) OR (ban thanh)) dai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach y nang x hoi. hieu van bac dac ((san thanh) OR (ban thanh)) dai cua tre*.