Perhaps you should try some spelling variations:
cau thuc » cau truc, cuu thuc, can thuc
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, mang may
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
kem cua » em cua, diem cua
keo cua » keo sua, kho cua, khoe cua
va cau » van cau, va cac, va dau

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 sach ky ((nang ma) OR (nang cao)) hoi. lieu va cau thuc va hanh ((kem cua) OR (keo cua)) triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang ma) OR (nang cao)) hoi. lieu va cau thuc va hanh ((kem cua) or (keo cua)) triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang ma) OR (nang cao)) hoi. lieu va cau thuc va hanh ((kem cua) or (keo cua)) triet*.