Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
nam thuc » nam thuoc, am thuc, nam thu
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
tang ma » mang may, tang van
su sach » so sach, vu sach
va nam » van nam, ha nam, va nay
vi cua » vai cua, di 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) or (su sach)) ky ((tang ma) or (nang cao)) hoi. lieu va nam thuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuoc sach) OR (su sach)) ky ((tang ma) OR (nang cao)) hoi. lieu va nam thuc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) or (su sach)) ky ((tang ma) or (nang cao)) hoi. lieu va nam thuc va hanh vi cua tre*.