Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
cua viet » ca viet, hoa viet, cua vat
te sach » toc sach
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
soc va » hoc va, loc va, goc va
doc va » duoc va, hoc va, duc va
vi cua » vai cua, di cua

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: ((te sach) OR (vu bach)) ky nang ma hoi. hieu van cham ((soc va) OR (doc va)) hanh vi cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (vu bach)) ky nang ma hoi. hieu van cham ((soc va) OR (doc va)) hanh vi cua viet~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (vu bach)) ky nang ma hoi. hieu van cham ((soc va) OR (doc va)) hanh vi cua viet*.