Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
tu sach » thu sach, su sach, te sach
tai cua » thai cua, tai cuc, tri cua
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, sang ma, nang cao
cho xu » chao xu, choi xu, cho xe
cho xa » cho ga, cho xe

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 ((nang ma) or (nang x)) hoi. hieu ve ((cho xu) OR (cho xa)) gia thanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang ma) OR (nang x)) hoi. hieu ve ((cho xu) OR (cho xa)) gia thanh tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang ma) or (nang x)) hoi. hieu ve ((cho xu) OR (cho xa)) gia thanh tai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang ma) or (nang x)) hoi. hieu ve ((cho xu) OR (cho xa)) gia thanh tai cua tre*.