Perhaps you should try some spelling variations:
ban hang » ngan hang
thuc ban » thuoc ban, thuc dan, thu ban
cau thuc » cau truc, cuu thuc, can thuc
su sach » so sach, vu sach
y nang » ky nang, ly nang, v nang
ve luu » ke luu, vi luu
va cau » van cau, va cac, va dau
o hai » co hai, so hai, o lai
o hoi » co hoi, o hoc, o hoa

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: su sach y nang ((o hoi) OR (o hai)). lieu va cau thuc ban hang ((ve luu) OR (ke suu)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang ((o hoi) OR (o hai)). lieu va cau thuc ban hang ((ve luu) or (ke suu)) tre~".
• Adding a wildcard symbol may retrieve word variants: su sach y nang ((o hoi) OR (o hai)). lieu va cau thuc ban hang ((ve luu) or (ke suu)) tre*.