Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
toc sach » hoc sach, doc sach, thuoc sach
va doanh » van doanh, vay doanh, va danh
cac thuc » cach thuc, cac thu, can thuc
dang xay » dang van, van xay
van cua » vang cua, ban cua, dan cua
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
dang xa » lang xa, dang ha, dang va
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac

You may be able to get more results by adjusting your search query.

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