Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
cau thuc » cau truc, cuu thuc, can thuc
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cua triet, dua tren
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
cuu tre » cau tren, cau treo
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
ve cau » ke cau, va cau, ve cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ky ((nang ma) or (tang ma)) hoi. hieu ve cau thuc va hanh di ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky ((nang ma) OR (tang ma)) hoi. hieu ve cau thuc va hanh di ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky ((nang ma) or (tang ma)) hoi. hieu ve cau thuc va hanh di ((cua tre) or (cuu tre))*.