The webapp provides for each item the link on ECB's website.
Speeches for : Willem F. Duisenberg where "adoption" appeared
2002-10-14 : Perspectives on EU enlargement2001-11-23 : The ECB and the accession process
2000-09-17 : The euro as a catalyst for legal convergence in Europe
1999-10-15 : EU enlargement, some views from the ECB