^Selart, Anti (2009). Jörn Staecker (ed.). "Baldwin von Alna, Dänemark und Rußland. Zur politischen Geschichte Livlands in den 1230er Jahren in "The Reception of Medieval Europe in the Baltic Sea Region" Papers of the XIIth Visby Symposium, Held at Gotland University, Visby". Acta Visbyensia (in German) (12). Gotland University Press: 59–74. ISBN9789197365352.