Perhaps you should try some spelling variations:
doanh cua » doanh luan
tu sach » thu sach, su sach, tu cach
cua cua » cua chua, ca cua, qua cua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
te sach » toc sach
xuc va » duc va, tuc va, luc va
ve cac » va cac, vien cac

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