Perhaps you should try some spelling variations:
thanh thai » thanh hai, thanh tai, nhanh thai
ban thanh » ban hanh, ban hang
hoc sach » hoc sinh, hoc cac, hoc anh
thai cua » than cua, tai cuc, tri cua
cuc ban » cua ban, cac ban, cuu ban
sach tu » sach thu, cach tu, sach ty
cua tre » cua te, cuu tre, cua triet
mau hoi » cau hoi, mai hoi, mau hop
tu dang » thu dang, tu dong, su dang
mau ho » mau hop, mau co, mau do
va cam » va cham, va cac, va cao
va co » vo co

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach tu dang ((mau hoi) OR (mau ho)). hieu ((va cam) or (va co)) cuc ban thanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach tu dang ((mau hoi) OR (mau ho)). hieu ((va cam) OR (va co)) cuc ban thanh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach tu dang ((mau hoi) OR (mau ho)). hieu ((va cam) or (va co)) cuc ban thanh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach tu dang ((mau hoi) OR (mau ho)). hieu ((va cam) or (va co)) cuc ban thanh thai cua tre*.