Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tu cach » tu cac
nang ma » tang ma, sang ma, nang cao
van cam » van nam, van lam, van dam
van cau » van dau, van hau, van chat
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
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: ((tu cach) or (toc sach)) ky nang ma hoa. hieu ((van cam) or (van cau)) thuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (toc sach)) ky nang ma hoa. hieu ((van cam) OR (van cau)) thuc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (toc sach)) ky nang ma hoa. hieu ((van cam) or (van cau)) thuc va hanh vi cua tre*.