Documents from four different archives were used: Gerhard Schröder's terms (1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005), Angela Merkel's 1st (2005Merkel's 1st ( -2009Merkel's 1st ( ), 2nd (2009Merkel's 1st ( -2013, and 3rd term (2013-2017).
the online archives are not homogeneous, there was no real classification for texts anterior to 2005, where a few unrelated speeches from other politicians are to be found.