Perhaps you should try some spelling variations:
van doanh » toan doanh, van dong, van thanh
viec cac » vien cac, viec lam, viec va
tai cua » thai cua, tai cuc, tri cua
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
ky lang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet
ha hoi » hoa hoi, xa hoi, va hoi
lo van » le van, vo van, so van

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky lang ((ha hoi) or (ha noi)). nhieu ((viec cac) OR (viec cua)) lo van doanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang ((ha hoi) OR (ha noi)). nhieu ((viec cac) OR (viec cua)) lo van doanh tai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang ((ha hoi) or (ha noi)). nhieu ((viec cac) OR (viec cua)) lo van doanh tai cua tre*".