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
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
tai cau » tai cac
tai cao » thai cao, tao cao, tai sao
tu sach » thu sach, su sach, te sach
ha hoi » hoa hoi, ha noi, va hoi
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 (xa hoi)). hieu viec cac lo van doanh ((tai cau) or (tai cao)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang ((ha hoi) OR (xa hoi)). hieu viec cac lo van doanh ((tai cau) OR (tai cao)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang ((ha hoi) OR (xa hoi)). hieu viec cac lo van doanh ((tai cau) or (tai cao)) triet*".