The webapp provides for each item the link on ECB's website.
Speeches for : Vitor Constancio where "prolonged" appeared
2014-12-15 : Nonlinearities in Macroeconomics and Finance2014-10-16 : Maintaining price stability in the euro area
2014-10-06 : A new phase of the ECB's monetary policy
2014-04-07 : Presentation of the ECB Annual Report 2013 to the Committee on Economic and Monetary Affairs of the European Parliament