Kramer, Heinrich Der Hexenhammer: Malleus Maleficarum. Kommentierte Neuübersetzung. Munich, 2000. Edited and translated by Wolfgang Behringer, Günter Jerouschek, and Werner Tschacher. Introduction by Wolfgang Behringer and Günter Jerouschek, see p. 7 available here.
In 1890, the scholar Hartmann Ammann located documents regarding Kramer's activities in Ravensburg and Innsbruck in the archives and printed them. Many are in Latin but there is one short message from Sigismund in German and can be found on page 83, here. It is written to Bishop of Brixen and expresses alarm and seems to request help bringing moderation to the activities of Kramer.
