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
cuu tre » cua tre, cau tren, cau treo
tu cao » cu cao, tu cac, vu cao
va dan » ca dan, va dao, va dau
di cuu » di cau, di cua, dinh cuu
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cao ky nang ((x hoi) or (o hoi)). hieu ve cham soc ((ban hang) or (va dan)) di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cao ky nang ((x hoi) OR (o hoi)). hieu ve cham soc ((ban hang) OR (va dan)) di cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu cao ky nang ((x hoi) or (o hoi)). hieu ve cham soc ((ban hang) or (va dan)) di cuu tre*.