Perhaps you should try some spelling variations:
doanh cua » doanh luan
hieu van » hieu va, thien van, lieu va
te sach » toc sach
nang xa » nang x, lang xa, nang ma
van cac » van hac, van cau, van bac
cua tre » cuu tre, cua triet, dua tren
sach ky » sac ky, sach y, sach ty
cua te » cua tu
loc va » hoc va, luc va
xuc va » duc va, tuc va, luc va

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: te sach ky nang xa hoi. hieu van cac ((xuc va) OR (loc va)) doanh cua ((cua tre) OR (cua te))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang xa hoi. hieu van cac ((xuc va) or (loc va)) doanh cua ((cua tre) OR (cua te))~".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang xa hoi. hieu van cac ((xuc va) or (loc va)) doanh cua ((cua tre) OR (cua te))*.