Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
lam quoc » lam duoc, nam quoc, lam thuoc
san benh » sau benh, tai benh, so benh
sach hoi » sach doi, sach moi, cach thoi
ban benh » ba benh, ban banh, can benh
hoi lang » hoa lang, hoi dan
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
va lam » van lam, va lap

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach hoi lang xa hoi. lieu va lam quoc ((ban benh) OR (san benh)) va ((cua tre) OR (cuu tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach hoi lang xa hoi. lieu va lam quoc ((ban benh) OR (san benh)) va ((cua tre) or (cuu tre))~".
• Adding a wildcard symbol may retrieve word variants: toc sach hoi lang xa hoi. lieu va lam quoc ((ban benh) OR (san benh)) va ((cua tre) or (cuu tre))*.