The webapp provides for each item the link on ECB's website.
Speeches for : Willem F. Duisenberg where "empirical" appeared
2002-07-05 : International Research Forum on Monetary Policy1999-12-03 : Monetary policy-making under uncertainty
1998-12-07 : The ESCB's stability-oriented monetary policy strategy
1998-12-03 : The role of monetary policy in economic policy