Perhaps you should try some spelling variations:
sach van » sach han, sach va, cach van
bach van » bach dan, cach van, bach dang
cuu thuc » cuu tac
van hanh » van thanh, ban hanh, van anh
hieu ve » hieu va, hieu van
hanh de » hanh ve, hanh kem
cua tre » cua te, cuu tre, cua triet
de cua » le cua, te cua, dieu cua
ban x » ban xu, ban _, ban 1
x hoi » xa hoi, o hoi, x ho

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 van) OR (bach van)) ban x hoi. hieu ve ((cuu thuc) or (cau truc)) van hanh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach van) OR (bach van)) ban x hoi. hieu ve ((cuu thuc) OR (cau truc)) van hanh de cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sach van) OR (bach van)) ban x hoi. hieu ve ((cuu thuc) or (cau truc)) van hanh de cua tre".
• Adding a wildcard symbol may retrieve word variants: so ((sach van) OR (bach van)) ban x hoi. hieu ve ((cuu thuc) or (cau truc)) van hanh de cua tre*.