Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
vu sach » vu bach, su sach, vu khach
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
hieu ve » hieu van
sach v » sach va, sach y, sach 2
vi cua » di cua
v nang » va nang, vu nang, van nang
x hoi » xa hoi, o hoi, x ho

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: vu sach v nang x hoi. ((hieu ve) OR (hieu va)) nam thuc va hanh ((vi cua) OR (vai cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach v nang x hoi. ((hieu ve) or (hieu va)) nam thuc va hanh ((vi cua) OR (vai cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: vu sach v nang x hoi. ((hieu ve) or (hieu va)) nam thuc va hanh ((vi cua) OR (vai cua)) tre*.