Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
va thanh » gia thanh, ban thanh, va tinh
dang xay » dang van, van xay
tu sach » thu sach, su sach, te sach
tai cua » thai cua, tai cuc, tri cua
cao duc » dao duc, cao suc, giao duc
hieu va » lieu va, hieu qua
lang xa » lang ha, lang van
cua tre » cua te, cuu tre, cua triet
va cao » va cac, va co, va dao

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 cao) or (((lang xa) OR (dang xay)))) hoi. hieu va cao duc va thanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang cao) OR (((lang xa) OR (dang xay)))) hoi. hieu va cao duc va thanh tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang cao) or (((lang xa) OR (dang xay)))) hoi. hieu va cao duc va thanh tai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang cao) or (((lang xa) OR (dang xay)))) hoi. hieu va cao duc va thanh tai cua tre*.