The webapp provides for each item the link on ECB's website.
Speeches for : Yves Mersch where "sui" appeared
2018-05-14 : Virtual currencies ante portas2018-02-14 : The role of euro banknotes as legal tender
2016-06-23 : Monetary policy in the euro area: scope, principles and limits
2016-04-09 : Scope and Limits of Monetary Policy