Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » thien van, lieu va
van hanh » van thanh, ban hanh, van anh
duc van » duc va, duc tan, duc manh
cao duc » dao duc, cao suc, giao duc
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
vi cua » vai cua, di cua
cua te » cua tu

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 ky lang xa hoi. ((((hieu ve) OR (hieu va))) OR (hieu van)) cao duc van hanh vi cua te~.
• Adding a wildcard symbol may retrieve word variants: hoc sach ky lang xa hoi. ((((hieu ve) or (hieu va))) or (hieu van)) cao duc van hanh vi cua te*.