Perhaps you should try some spelling variations:
vay doanh » van doanh, ly doanh, voi doanh
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
vay doan » van doan, van doanh, tap doan
cac tac » cac toc, cac bac, cac dac
van cua » vang cua, ban cua, dan cua
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
cac tuc » cac toc, cac tu, cac nuoc
danh xa » danh ca, dinh xa, canh xa
ty danh » ty doanh, ty anh, ky danh

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ty danh xa hoi. hieu van ((cac tuc) OR (cac tac)) ((vay doan) or (vay doanh)) van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty danh xa hoi. hieu van ((cac tuc) OR (cac tac)) ((vay doan) OR (vay doanh)) van cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty danh xa hoi. hieu van ((cac tuc) OR (cac tac)) ((vay doan) or (vay doanh)) van cua tre*".