Perhaps you should try some spelling variations:
doanh dai » doanh tai, doanh dao, doanh giai
ban doanh » van doanh, san doanh, ban danh
toc sach » hoc sach, doc sach, thuoc sach
cham duc » pham duc, cham soc, pham duy
van cham » van chat, van tham, va cham
hieu van » hieu va, thien van, lieu va
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet
dao tay » dao tao, dan tay

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