Perhaps you should try some spelling variations:
van doanh » toan doanh, van dong, van thanh
hieu viec » nhieu viec, hieu ve, sieu viet
viec cac » vien cac, viec cua, viec lam
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
tai cuu » tai cuc, tai buu, tai cua
cuu tre » cua tre, cau tren, cau treo
ky lang » ky nang, ky dang, ky tang
ha hoi » hoa hoi, va hoi, ha hoa
cac lo » cac lop, cac co, cac bo
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))) or (xa hoi)). hieu viec cac lo van doanh tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang ((((ha hoi) OR (ha noi))) OR (xa hoi)). hieu viec cac lo van doanh tai cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang ((((ha hoi) OR (ha noi))) or (xa hoi)). hieu viec cac lo van doanh tai cuu tre*".