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