Perhaps you should try some spelling variations:
bac thuc » bao thuc, bac thua, cach thuc
su sach » so sach, vu sach
so sanh » do sanh
cao hoi » cau hoi, co hoi, cao hoc
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
v nang » va nang, vu nang, van nang
va bac » van bac, va cac, va bai
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: ((su sach) or (so sanh)) v nang cao hoi. lieu va bac thuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sanh)) v nang cao hoi. lieu va bac thuc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sanh)) v nang cao hoi. lieu va bac thuc va hanh vi cua tre*.