Perhaps you should try some spelling variations:
nang cau » nang cao, hang cau, nang dau
hieu van » hieu va, thien van, hieu ve
nam thuc » nam thuoc, am thuc, nam thu
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
luu tre » luu tru, luy tre
cuu tre » cua tre, cau tren, cau treo
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky

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 sac ky nang cau hoi. ((hieu van) OR (lieu va)) nam thuc va hanh vi ((luu tre) OR (cuu tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky nang cau hoi. ((hieu van) or (lieu va)) nam thuc va hanh vi ((luu tre) OR (cuu tre))~".
• Adding a wildcard symbol may retrieve word variants: te sac ky nang cau hoi. ((hieu van) or (lieu va)) nam thuc va hanh vi ((luu tre) OR (cuu tre))*.