Perhaps you should try some spelling variations:
hanh dieu » han dieu, hinh dieu, hoang dieu
hieu van » thien van, lieu va
van nang » van quang, van ban, van dong
dieu cua » dieu tra
ban hanh » ban hang
thuc ban » thuoc ban, thuc dan, thu ban
cau thuc » cau truc, cuu thuc, can thuc
sach van » sach han, sach va, bach van
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
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 va))) or (hieu van)) cau thuc ban hanh dieu 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 va))) OR (hieu van)) cau thuc ban hanh dieu cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach van nang x hoi. ((((hieu ve) OR (hieu va))) or (hieu van)) cau thuc ban hanh dieu cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach van nang x hoi. ((((hieu ve) OR (hieu va))) or (hieu van)) cau thuc ban hanh dieu cua tre*.