Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
van hanh » van thanh, ban hanh, van anh
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
soc van » hoc van, oc van, sac van
voi cac » loi cach
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: so sach ky nang x hoi. hieu van cham soc van hanh ((va cac) or (voi cac)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang x hoi. hieu van cham soc van hanh ((va cac) OR (voi cac)) tren.
• Adding a wildcard symbol may retrieve word variants: so sach ky nang x hoi. hieu van cham soc van hanh ((va cac) or (voi cac)) tren*.