Stephens, W. P. „The Sacraments in the Confessions of 1536, 1549, and 1566: Bullinger’s Understanding in the Light of Zwingli’s“. Zwingliana, Bd. 33, Nr. , Januar 2010, S. 51-76, https://www.zwingliana.ch/index.php/zwa/article/view/93.