Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
ban thanh » ban hanh
vu khach » vu khanh, vu khac, vay khach
khach ky » hanh ky, thanh ky
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
ban hang » ngan hang
cua tre » cua te, cuu tre, dua tren
x hoi » xa hoi, o hoi, x ho

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 x hoi. hieu van nam thuc ((ban thanh) or (ban hang)) vi ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu khach ky nang x hoi. hieu van nam thuc ((ban thanh) OR (ban hang)) vi ((cua tre) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: vu khach ky nang x hoi. hieu van nam thuc ((ban thanh) or (ban hang)) vi ((cua tre) or (cua triet))*.