Perhaps you should try some spelling variations:
22neglected diseases » neglected diseases, neglected disease, selected diseases
proof prevention » proof preventing, proof presentation, probes prevention
2f prevention » f prevention, 2f prediction, serif prevention
26 control » 6 control, 12.6 control, 3.6 control
16 control » 6 control

Try widening your search to All Fields.

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: %22neglected diseases %((2f prevention) OR (proof prevention)) %((26 control) OR (16 control))%22.
• The words AND, OR and NOT may confuse the search; try adding quotes: "%22neglected diseases %((2f prevention) or (proof prevention)) %((26 control) OR (16 control))%22".
• Adding a wildcard symbol may retrieve word variants: %22neglected diseases %((2f prevention) or (proof prevention)) %((26 control) OR (16 control))%22*.