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

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