Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
dua tren » dung tren
va hanh » van hanh, va thanh, va danh
cua tre » cuu tre, cua triet, cua thep
sach 2 » sach y
2 nang » v nang
va cao » va cac, va co, va dao
cua te » cua tu
x hoi » xa hoi, o hoi, x ho
su va » su van, tu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach 2 nang x hoi. lieu va cao su va hanh vi ((((cua tre) or (dua tren))) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach 2 nang x hoi. lieu va cao su va hanh vi ((((cua tre) OR (dua tren))) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: hoc sach 2 nang x hoi. lieu va cao su va hanh vi ((((cua tre) or (dua tren))) or (cua te))*.