Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
thuc dan » thuc hanh, hoc dan, thuc vat
thuc day » thuc vat
sach ky » sac ky, sach y, sach ty
ky danh » ky anh, ky dang
danh ma » anh ma, danh ca, hanh ma
van cam » van nam, van lam, van cau
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: toc sach ky danh ma hoa. hieu van cam ((thuc dan) or (thuc day)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky danh ma hoa. hieu van cam ((thuc dan) OR (thuc day)) hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky danh ma hoa. hieu van cam ((thuc dan) or (thuc day)) hanh vi cua tre*.