Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh vi » hanh vi, thanh va, thanh ve
sach thu » sach thue, sach thieu, sach tham
chat xuc » chat huu, cam xuc, chao xu
xuc ban » duc ban, cuc ban, quoc ban
va chat » van chat, va phat, cao chat
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, xach tay
vi cua » vai cua, di cua
x hoi » xa hoi, x ho, 5 hoi
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 ty) or (sach thu)) nang ((x hoi) OR (o hoi)). hieu va chat xuc ban thanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thu)) nang ((x hoi) OR (o hoi)). hieu va chat xuc ban thanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) or (sach thu)) nang ((x hoi) OR (o hoi)). hieu va chat xuc ban thanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach thu)) nang ((x hoi) OR (o hoi)). hieu va chat xuc ban thanh vi cua tre*.