Perhaps you should try some spelling variations:
hanh dieu » han dieu, hinh dieu, hoang dieu
sach van » sach han, sach va, bach van
van nang » van quang, van ban, van dong
cau thuc » cuu thuc, can thuc, cau phuc
van hanh » van thanh, ban hanh, van anh
dieu cua » dieu tra
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
o hoi » co hoi, o hoc, o hai

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 van nang ((x ho) or (o hoi)). hieu qua ((cau thuc) or (cau truc)) van hanh dieu cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach van nang ((x ho) OR (o hoi)). hieu qua ((cau thuc) OR (cau truc)) van hanh dieu cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach van nang ((x ho) or (o hoi)). hieu qua ((cau thuc) or (cau truc)) van hanh dieu cua tre*.