Perhaps you should try some spelling variations:
tang thanh » dang thanh, trung thanh, hoang thanh
thanh vai » thanh hai, thanh van, thanh tai
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
ban duc » ban duoc, van duc, tran duc
ban dac » ban dan, ban dau, ban sac
vai cua » dai cua, hai cua, lai cua
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: tu sach y nang x hoi. hieu van ((ban duc) or (ban dac)) tang thanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang x hoi. hieu van ((ban duc) OR (ban dac)) tang thanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang x hoi. hieu van ((ban duc) or (ban dac)) tang thanh vai cua tre*.