Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
cua viet » ca viet, hoa viet, cua vat
te sach » toc sach
vu sach » vu bach, su sach, vu khach
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
soc va » hoc va, loc va, doc 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 sach)) y nang ma hoi. ((hieu van) OR (hieu va)) cham soc va hanh vi cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (vu sach)) y nang ma hoi. ((hieu van) OR (hieu va)) cham soc va hanh vi cua viet~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (vu sach)) y nang ma hoi. ((hieu van) OR (hieu va)) cham soc va hanh vi cua viet*.