M. Starnawska, “Darius von Güttner-Sporzyński, Poland, Holy War and the Piast Monarchy, 1100–1230 (Europa Sacra 14), Brepols, Turnohout 2014, XII + 294 pp. + maps, ISBN: 978-2-503-54794-7”, OM, vol. 21, pp. 223–228, May 2017.