Perhaps you should try some spelling variations:
sach van » sach han, sach va, bach van
van nang » van quang, van ban, van dong
hieu van » hieu va, thien van, lieu va
cau thuc » cau truc, cuu thuc, can thuc
thuc ban » thuoc ban, thuc dan, thu ban
ban hanh » ban hang
su sach » so sach, vu sach
hieu ve » hieu va
hanh de » hanh ve, hanh kem
cua tre » cua te, cuu tre, cua triet
de cua » le cua, te cua, dieu cua
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: su sach van nang x hoi. ((hieu ve) or (hieu van)) cau thuc ban hanh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach van nang x hoi. ((hieu ve) OR (hieu van)) cau thuc ban hanh de cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach van nang x hoi. ((hieu ve) or (hieu van)) cau thuc ban hanh de cua tre*.