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
vu khac » vu kham, vu khanh, bui khac
van cau » van dau, van hau, van chat
va hanh » van hanh, va thanh, va danh
su tien » su kien, su hien, tu tieng
cau tu » dau tu, cau truc
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 cau tu ((ban thanh) or (va hanh)) ki su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu khach) OR (vu khac)) ky nang x ho. hieu van cau tu ((ban thanh) OR (va hanh)) ki su tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu khach) OR (vu khac)) ky nang x ho. hieu van cau tu ((ban thanh) or (va hanh)) ki su tien".
• Adding a wildcard symbol may retrieve word variants: ((vu khach) OR (vu khac)) ky nang x ho. hieu van cau tu ((ban thanh) or (va hanh)) ki su tien*.