Perhaps you should try some spelling variations:
hieu viec » nhieu viec, hieu ve, sieu viet
doanh thu » doanh tai
viec ban » viec lam, viec va, viec tai
ban nuoc » ban duoc, ban nuoi, ban thuoc
danh tu » anh tu
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
sac ky » cac ky, sai ky
so sac » so sach, so dac

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: so sac ky ((nang xa) OR (nang ma)) hoi. hieu viec ban nuoc va ((danh tu) OR (doanh thu)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sac ky ((nang xa) or (nang ma)) hoi. hieu viec ban nuoc va ((danh tu) OR (doanh thu)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: so sac ky ((nang xa) or (nang ma)) hoi. hieu viec ban nuoc va ((danh tu) OR (doanh thu)) cua tre*.