Perhaps you should try some spelling variations:
va thieu » va thiet, va hieu, va tieu
sach hay » sach han, sach nay, sach vay
hieu van » hieu va, thien van, lieu va
hang vi » hanh vi, hang di, khang voi
cac toc » cac toi, cac nuoc, cac thoi
lang xa » lang ha, dang xay, lang van
sach ha » sach nha, sach han, sach xa
van cac » van hac, van cau, van bac
toc va » hoc va, toc ta, tuc va

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: tu ((sach hay) OR (sach ha)) lang xa hoi. hieu van cac toc va ((hang vi) OR (hang va)) va thieu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach hay) OR (sach ha)) lang xa hoi. hieu van cac toc va ((hang vi) or (hang va)) va thieu~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach hay) OR (sach ha)) lang xa hoi. hieu van cac toc va ((hang vi) or (hang va)) va thieu*.