Perhaps you should try some spelling variations:
sach nham » sach nha, sach tham, sach han
lam thuc » lam thuoc, am thuc, nam thuc
hieu van » hieu va, thien van, lieu va
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
so sach » so sanh, bo sach, co sach
nang ma » tang ma, sang ma, mang may
van lam » van nam
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach nham ((nang ma) OR (nang cao)) hoi. hieu van lam thuc va hanh ((di cua) or (vai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach nham ((nang ma) OR (nang cao)) hoi. hieu van lam thuc va hanh ((di cua) OR (vai cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach nham ((nang ma) OR (nang cao)) hoi. hieu van lam thuc va hanh ((di cua) or (vai cua)) triet".
• Adding a wildcard symbol may retrieve word variants: so sach nham ((nang ma) OR (nang cao)) hoi. hieu van lam thuc va hanh ((di cua) or (vai cua)) triet*.