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
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
ve cau » ke cau, va cau, ve cac
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: thuoc sach ky ((nang ma) or (sang ma)) hoi. hieu ve cau thuc va hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky ((nang ma) OR (sang ma)) hoi. hieu ve cau thuc va hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky ((nang ma) or (sang ma)) hoi. hieu ve cau thuc va hanh di cua tre*.