Perhaps you should try some spelling variations:
te sach » toc sach
tinh vi » trinh vi, tinh voi, tinh va
va tinh » may tinh
cac duc » cac du, cao duc, cac dac
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
hieu ve » hieu van
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, di cua

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

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