Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
vu khach » vu khanh, vay khach, cua khach
hieu van » hieu va, thien van, lieu va
su triet » su viet, su tien, ve triet
vu khac » vu kham, vu khanh, bui khac
van cam » van nam, van lam, van cau
va danh » va dinh, va dan, va hanh
cam tu » cam thu, nam tu, dam tu
ki su » ky su

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) OR (vu khac)) ky nang x ho. hieu van cam tu ((ban thanh) or (va danh)) ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu khach) OR (vu khac)) ky nang x ho. hieu van cam tu ((ban thanh) OR (va danh)) ki su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu khach) OR (vu khac)) ky nang x ho. hieu van cam tu ((ban thanh) or (va danh)) ki su triet".
• Adding a wildcard symbol may retrieve word variants: ((vu khach) OR (vu khac)) ky nang x ho. hieu van cam tu ((ban thanh) or (va danh)) ki su triet*.