Perhaps you should try some spelling variations:
sieu viet » su viet, dien viet, bien viet
hieu viec » nhieu viec, hieu ve, hieu hien
van doanh » toan doanh, van dong, van thanh
doanh va » doan va, doanh tai, doanh cua
cua tre » cua te, cua triet, dua tren
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
cuu tre » cau tren, cau treo
cac so » cac co, cac bo, cac ho
so van » su van, vo van

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang xa hoi. ((hieu viec) OR (sieu viet)) cac so van doanh va ((cua tre) OR (cuu tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang xa hoi. ((hieu viec) OR (sieu viet)) cac so van doanh va ((cua tre) or (cuu tre))~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. ((hieu viec) OR (sieu viet)) cac so van doanh va ((cua tre) or (cuu tre))*.