Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu xang » thu hang, thu bang, thu dang
so sach » so sanh, bo sach, co sach
van cau » van dau, van hau, van chat
xang xa » lang xa, mang xa, ang xa
van cac » van hac, van bac, dan cac
cua tre » cua te, cuu tre, cua triet
xac va » tac va, ac va, bac va
tuc va » thuc va, truc va, tuc xa
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 thu xang xa hoi. hieu ((van cac) OR (van cau)) ((xac va) or (tuc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach thu xang xa hoi. hieu ((van cac) OR (van cau)) ((xac va) OR (tuc va)) hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach thu xang xa hoi. hieu ((van cac) OR (van cau)) ((xac va) or (tuc va)) hanh vi cua tre*".