Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va
thuc va » thuc vat, thuc dan, thuc day
va tinh » may tinh
tu bai » tu ban, tu bat, te bai
bai ky » ban ky, sai ky, bac ky
te cua » le cua, de 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: tu bai ky nang ma hoa. ((hieu ve) OR (hieu van)) am thuc va tinh ((te cua) OR (tue cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu bai ky nang ma hoa. ((hieu ve) or (hieu van)) am thuc va tinh ((te cua) OR (tue cua)) tre~".
• Adding a wildcard symbol may retrieve word variants: tu bai ky nang ma hoa. ((hieu ve) or (hieu van)) am thuc va tinh ((te cua) OR (tue cua)) tre*.