Perhaps you should try some spelling variations:
ban hang » ngan hang
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
va danh » va dinh, va dan, va hanh
cau tre » cau tren, cau treo, cau tra
co hoi » co hoc, co loi
di cau » da cau, diem cau
o hoi » o hoc, o hai, 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: tu cac ky nang ((o hoi) OR (co hoi)). hieu ve cham soc ((ban hang) or (va danh)) di cau tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky nang ((o hoi) OR (co hoi)). hieu ve cham soc ((ban hang) OR (va danh)) di cau tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac ky nang ((o hoi) OR (co hoi)). hieu ve cham soc ((ban hang) or (va danh)) di cau tre".
• Adding a wildcard symbol may retrieve word variants: tu cac ky nang ((o hoi) OR (co hoi)). hieu ve cham soc ((ban hang) or (va danh)) di cau tre*.