Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
nam thuc » nam thuoc, am thuc, nam thu
danh vai » danh sai, danh va, dang van
tu sach » thu sach, te sach, tu cach
thuc va » thuc vat, thuc dan, thuc day
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va, hieu van
mang xa » lang xa, mang may, dang xay
ty mang » ty xang, ty hang, tin mang
su sach » so sach, vu sach
ve nam » he nam, va nam, le nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) OR (su sach)) ty mang xa hoi. hieu ve nam thuc va ((danh vai) or (doanh van)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ty mang xa hoi. hieu ve nam thuc va ((danh vai) OR (doanh van)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ty mang xa hoi. hieu ve nam thuc va ((danh vai) or (doanh van)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ty mang xa hoi. hieu ve nam thuc va ((danh vai) or (doanh van)) cuu tre*.