Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
truc van » truc va, thuc van, truc ban
dua tren » dung tren
cua tre » cuu tre, cua triet, cua thep
hanh de » hanh ve, hanh kem
sach va » sach xa, sach ha, sach dao
so sach » so sanh, bo sach, co sach
hieu va » lieu va, hieu qua
va cau » van cau, va cac, va dau
va ban » van ban, va bai, va bao
cua te » cua tu
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.

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