Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
hieu va » lieu va, hieu qua
thuc va » thuc dan, thuc day
cuu tre » cua tre, cau tren, cau treo
va cao » va cac, va co, va dao
vi cuu » vi luu, vinh cuu
x hoi » xa hoi, o hoi, x ho

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 tu nang x hoi. hieu va cao ((thuc va) or (thuc vat)) hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tu nang x hoi. hieu va cao ((thuc va) OR (thuc vat)) hanh vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: toc sach tu nang x hoi. hieu va cao ((thuc va) or (thuc vat)) hanh vi cuu tre*.