Perhaps you should try some spelling variations:
doanh dai » doanh tai, doanh dao, doanh giai
dang xay » dang van, van xay
toc sach » hoc sach, doc sach, thuoc sach
va doanh » van doanh, vay doanh, va danh
hieu van » hieu va, thien van, lieu va
cac toc » cac toi, cac nuoc, cac thoi
van cac » van hac, van cau, van bac
lang xa » lang ha, lang van
toc va » hoc va, toc ta, tuc va
cua te » cua tu

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) OR (toc sach)) ky ((lang xa) OR (dang xay)) hoi. hieu van cac toc va doanh dai cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky ((lang xa) or (dang xay)) hoi. hieu van cac toc va doanh dai cua te~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky ((lang xa) or (dang xay)) hoi. hieu van cac toc va doanh dai cua te*.