Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cac quoc » cac nuoc, cac cuoc, cao quoc
ban benh » ba benh, ban banh, can benh
san benh » sau benh, tai benh, so benh
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
y lang » o lang, _ lang, tay lang
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 y lang xa hoi. hieu va cac quoc ((ban benh) or (san benh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y lang xa hoi. hieu va cac quoc ((ban benh) OR (san benh)) vi cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach y lang xa hoi. hieu va cac quoc ((ban benh) or (san benh)) vi cua tre*.