The webapp provides for each item the link on ECB's website.
Speeches for : Jurgen Stark where "credible" appeared
2011-02-21 : Central banking after the financial crisis2009-09-15 : Monetary and fiscal policy: criteria and timing for the phasing out of crisis measures
2009-06-08 : The economic crisis and the response of fiscal and monetary policy
2007-11-26 : Delivering price stability: benefits and challenges