Perhaps you should try some spelling variations:
doanh dan » doanh ban, doanh van, doanh dao
hieu van » hieu va, thien van, lieu va
te sach » toc sach
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
van cac » van hac, van cau, van bac
sach ky » sac ky, sach y, sach ty
cua te » cua tu
toc va » toc ta, tuc va, loc va
cua cu » cua chu, cua cau, cua su

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