Perhaps you should try some spelling variations:
ban doanh » van doanh, san doanh, toan doanh
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
cham duc » pham duc, cham soc, pham duy
ban danh » ban hanh, ban dan, van danh
te sach » toc sach
dao tay » dao tao, dan tay
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y ((dung tai) or (dao tay)) hoi. hieu van cham duc ((ban doanh) OR (ban danh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((dung tai) OR (dao tay)) hoi. hieu van cham duc ((ban doanh) OR (ban danh)) dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y ((dung tai) or (dao tay)) hoi. hieu van cham duc ((ban doanh) OR (ban danh)) dai cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach y ((dung tai) or (dao tay)) hoi. hieu van cham duc ((ban doanh) OR (ban danh)) dai cua tre*.