Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cau thuc » cuu thuc, can thuc, cau phuc
su sach » so sach
hanh de » hanh ve, hanh kem
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
vu sach » vu bach, vu khach
de cua » le cua, te cua, dieu cua
x hoi » xa hoi, o hoi, x ho
ban x » ban xu, ban _, ban 1

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

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