Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
ban hanh » ban hang
van cau » van dau, van hau, van chat
hanh de » hanh ve, hanh kem
duc ban » duc tan, duc van, dua ban
van cam » van nam, van lam, van dam
cua tre » cua te, cuu tre, cua triet
de cua » le cua, te cua, dieu cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((tu nano) or (truc nano)) xa hoi. hieu ((van cam) OR (van cau)) duc ban hanh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((tu nano) OR (truc nano)) xa hoi. hieu ((van cam) OR (van cau)) duc ban hanh de cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((tu nano) or (truc nano)) xa hoi. hieu ((van cam) OR (van cau)) duc ban hanh de cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ((tu nano) or (truc nano)) xa hoi. hieu ((van cam) OR (van cau)) duc ban hanh de cua tre*.