Perhaps you should try some spelling variations:
doanh dan » doanh ban, doanh van, doanh dao
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
va doanh » van doanh, vay doanh, va danh
hieu van » hieu va, thien van, lieu va
hac toc » thac toc, cac toc
dan cua » dan ca, ban cua, dai cua
lang xa » lang ha, dang xay, lang van
van hac » van hoc, van ha, van hai
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.

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) OR (hoc sach)) ky ((lang xa) or (hang va)) hoi. hieu van hac toc va doanh dan cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ky ((lang xa) OR (hang va)) hoi. hieu van hac toc va doanh dan cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (hoc sach)) ky ((lang xa) or (hang va)) hoi. hieu van hac toc va doanh dan cua te*".