Perhaps you should try some spelling variations:
sach tham » sach nha
hieu van » hieu va, thien van, lieu va
sach thu » sach thue, sach thieu, cach thuc
van hanh » van thanh, ban hanh, van anh
cuu thuc » cuu tac
can thuc » dan thuc, van thuc, cay thuc
hang co » hang cho, hang ca, nang co
cua tre » cua te, cuu tre, cua triet
co loi » co hoi
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: te ((sach thu) OR (sach tham)) hang co loi. hieu van ((can thuc) or (cuu thuc)) van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach thu) OR (sach tham)) hang co loi. hieu van ((can thuc) OR (cuu thuc)) van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach thu) OR (sach tham)) hang co loi. hieu van ((can thuc) or (cuu thuc)) van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach thu) OR (sach tham)) hang co loi. hieu van ((can thuc) or (cuu thuc)) van hanh vi cua tre*.