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
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
lo van » le van, vo van, so van
lo va » lao va, ly va, le va

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 ma) or (tang ma)) hoi. hieu va cac ((lo va) or (lo van)) thanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang ma) OR (tang ma)) hoi. hieu va cac ((lo va) OR (lo van)) thanh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang ma) or (tang ma)) hoi. hieu va cac ((lo va) or (lo van)) thanh tai cua tre*.