Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
so sach » so sanh, co sach, hoc sach
van cac » van hac, van cau, van bac
xang xa » lang xa, mang xa, ang xa
bo sach » co sach, hoc sach
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, xac va
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((so sach) OR (bo sach)) ty xang xa hoi. hieu van cac ((xuc va) or (luc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (bo sach)) ty xang xa hoi. hieu van cac ((xuc va) OR (luc va)) hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) OR (bo sach)) ty xang xa hoi. hieu van cac ((xuc va) or (luc va)) hanh vi cua tre*".