Perhaps you should try some spelling variations:
cam quoc » cac quoc, cao quoc, nam quoc
ban benh » san benh, ban banh, can benh
te sach » toc sach
lang xa » lang ha, dang xay, lang van
hieu va » lieu va
ba benh » va benh, bo benh, bach benh
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: te sach y lang xa hoi. ((hieu va) or (hieu qua)) cam quoc ((ban benh) OR (ba benh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y lang xa hoi. ((hieu va) OR (hieu qua)) cam quoc ((ban benh) OR (ba benh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y lang xa hoi. ((hieu va) or (hieu qua)) cam quoc ((ban benh) OR (ba benh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach y lang xa hoi. ((hieu va) or (hieu qua)) cam quoc ((ban benh) OR (ba benh)) vi cua tre*.