Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
tinh dat » tinh da, dinh dat, tinh dau
dat cua » dai cua, day cua, mat cua
va tinh » may tinh
hieu va » lieu va, hieu qua
hieu ve » hieu van
mai hoi » mai khoi, dai hoi, lai hoi
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
cac tu » cac thu, cach tu, cac du
ma hoi » xa hoi, ma hoa, me hoi

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: hoc sach y nang ((ma hoi) OR (mai hoi)). ((hieu ve) OR (hieu va)) cac tu va tinh dat cua tre~.
• Adding a wildcard symbol may retrieve word variants: hoc sach y nang ((ma hoi) or (mai hoi)). ((hieu ve) or (hieu va)) cac tu va tinh dat cua tre*.