The webapp provides for each item the link on ECB's website.
Speeches for : Vitor Constancio where "serves" appeared
2017-11-24 : Ricardo Reis’ contribution to Macroeconomics2017-05-25 : The future of monetary policy frameworks
2015-01-31 : Monetary policy challenges in the euro area
2013-09-27 : Deutsche Bank Prize attribution to Raghuram Rajan
2011-12-08 : Challenges to monetary policy in 2012
2011-11-23 : The Future of the International Monetary System