Perhaps you should try some spelling variations:
tinh binh » ninh binh, tinh ninh
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
thuc va » thuc vat, thuc dan, thuc day
chi tre » choi tre, chi tro, chi tiet
va tinh » may tinh
cho tre » cho thue, khoe tre
sang ma » tang ma, nang ma, sang tao
sai ky » sac ky
tu sai » tu bai, tu san, tu cai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sai ky ((nang cao) or (sang ma)) hoi. hieu van nam thuc va tinh binh ((chi tre) OR (cho tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sai ky ((nang cao) OR (sang ma)) hoi. hieu van nam thuc va tinh binh ((chi tre) OR (cho tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sai ky ((nang cao) or (sang ma)) hoi. hieu van nam thuc va tinh binh ((chi tre) OR (cho tre))".
• Adding a wildcard symbol may retrieve word variants: tu sai ky ((nang cao) or (sang ma)) hoi. hieu van nam thuc va tinh binh ((chi tre) OR (cho tre))*.