Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dang xay » dang van, van xay
hieu van » hieu va, thien van, lieu va
cac quoc » cac nuoc, cac cuoc, cao quoc
ban benh » ba benh, ban banh, can benh
san benh » sau benh, tai benh, so benh
xay hoi » xa hoi, tay hoi, cay phoi
van cac » van hac, van cau, van bac
cuu tre » cua tre, cau tren, cau treo
y dang » ky dang, 2 dang, _ dang
vi cuu » vi luu, vinh cuu

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 dang xay hoi. hieu van cac quoc ((ban benh) or (san benh)) vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y dang xay hoi. hieu van cac quoc ((ban benh) OR (san benh)) vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: toc sach y dang xay hoi. hieu van cac quoc ((ban benh) or (san benh)) vi cuu tre*.