The webapp provides for each item the link on ECB's website.
Speeches for : Vitor Constancio where "slope" appeared
2017-09-22 : Understanding and overcoming low inflation2015-11-05 : Understanding Inflation Dynamics and Monetary Policy in a Low Inflation Environment
2015-08-29 : Understanding Inflation Dynamics and Monetary Policy
2014-09-08 : Understanding the yield curve