Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
vu sach » vu bach, su sach, vu khach
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu van
vi cua » vai cua, di cua
cua te » cua tu
y nang » ky nang, ly nang, may nang
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.

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ((y nang) OR (v nang)) x hoi. ((hieu ve) or (hieu va)) nam thuc va hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ((y nang) OR (v nang)) x hoi. ((hieu ve) OR (hieu va)) nam thuc va hanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ((y nang) OR (v nang)) x hoi. ((hieu ve) or (hieu va)) nam thuc va hanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: vu sach ((y nang) OR (v nang)) x hoi. ((hieu ve) or (hieu va)) nam thuc va hanh vi cua te*.