The webapp provides for each item the link on ECB's website.
Speeches for : Vitor Constancio where "buy" appeared
2017-02-03 : Resolving Europe's NPL burden: challenges and benefits2014-10-06 : A new phase of the ECB's monetary policy
2014-09-11 : Interview with Börsen-Zeitung
2012-08-02 : Introductory statement to the press conference (with Q&A)