Perhaps you should try some spelling variations:
doanh cua » doanh luan
vien cac » vien bach, vien dai, vien da
tu sach » thu sach, su sach, te sach
cua cua » cua chua, ca cua, qua cua
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
ve cac » va 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 ky nang xa hoi. hieu ((ve cac) OR (vien cac)) ((xuc va) or (tuc va)) doanh cua cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu ((ve cac) OR (vien cac)) ((xuc va) OR (tuc va)) doanh cua cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu ((ve cac) OR (vien cac)) ((xuc va) or (tuc va)) doanh cua cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu ((ve cac) OR (vien cac)) ((xuc va) or (tuc va)) doanh cua cua tre*.