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

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