Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
can thuc » dan thuc, van thuc, cay thuc
danh de » hanh de, dang de, danh di
thuc va » thuc vat, thuc dan, thuc day
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
dan de » dan den, dang de, van de
ve can » ve canh, ve cac, ve ban

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 can thuc va ((danh de) OR (dan de)) 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 can thuc va ((danh de) OR (dan de)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ky ((nang ma) or (sang ma)) hoi. hieu ve can thuc va ((danh de) OR (dan de)) cua tre".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky ((nang ma) or (sang ma)) hoi. hieu ve can thuc va ((danh de) OR (dan de)) cua tre*.