Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
can thuc » dan thuc, van thuc, cay thuc
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 danh » va dinh, va dan, va hanh
danh de » hanh de, dan de, dang de
cua tre » cua te, cuu tre, cua triet
ve can » ve canh, ve cac, ve ban
de cua » le cua, te cua, dieu 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 y ((nang ma) or (sang ma)) hoi. hieu ve can thuc va danh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach y ((nang ma) OR (sang ma)) hoi. hieu ve can thuc va danh de cua tre.
• Adding a wildcard symbol may retrieve word variants: thuoc sach y ((nang ma) or (sang ma)) hoi. hieu ve can thuc va danh de cua tre*.