Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
va thanh » gia thanh, va tinh, le thanh
dang xay » dang van, van xay
te sach » toc sach
cac tuc » cac toc, cac tu, cac tac
hieu va » lieu va, hieu qua
sach tu » sach thu, cach tu, sach ty
lang xa » lang ha, lang van
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

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

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