Perhaps you should try some spelling variations:
doanh dan » doanh ban, doanh van, doanh dao
toc sach » hoc sach, thuoc sach, nuoc sach
hieu van » hieu va, thien van, lieu va
doc sach » hoc sach, nuoc sach, dac sac
va doanh » van doanh, vay doanh, va danh
cac toc » cac toi, cac nuoc, cac thoi
van cac » van hac, van cau, van bac
lang xa » lang ha, dang xay, lang van
ty lang » tay lang, ty xang, ty hang
toc va » hoc va, toc ta, tuc va
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: ((toc sach) OR (doc sach)) ty lang xa hoi. hieu van cac toc va doanh dan ((cua te) OR (cua tu))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ty lang xa hoi. hieu van cac toc va doanh dan ((cua te) or (cua tu))~".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) ty lang xa hoi. hieu van cac toc va doanh dan ((cua te) or (cua tu))*.