Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
ban thanh » ban hanh, ban hang
thuoc ban » thuoc tan, thuoc dang, thu ban
vu khach » vu khanh, vu khac, vay khach
khach ky » hanh ky, thanh ky
vai cua » dai cua, hai cua, lai cua
hieu ve » hieu va, hieu van
vi cua » di cua
ve nam » he nam, va nam, le nam
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.

• Performing a fuzzy search may retrieve terms with similar spellings: vu khach ky nang ((o hoi) OR (o hai)). hieu ve nam thuoc ban thanh ((vi cua) or (vai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu khach ky nang ((o hoi) OR (o hai)). hieu ve nam thuoc ban thanh ((vi cua) OR (vai cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu khach ky nang ((o hoi) OR (o hai)). hieu ve nam thuoc ban thanh ((vi cua) or (vai cua)) te".
• Adding a wildcard symbol may retrieve word variants: vu khach ky nang ((o hoi) OR (o hai)). hieu ve nam thuoc ban thanh ((vi cua) or (vai cua)) te*.