Bak & Rady 2010, pp. xlii–xliii. Roger was back in James's service in 1236–1239, but he returned again to Hungary in time to experience Mongol invasion of 1241. He wrote an eyewitness account of the destruction in his Carmen miserabile. According to Carpegna Falconieri 2005, Tedaldo Visconti, the future Pope Gregory X, was another member of James's early legations. Bak, János M.; Rady, Martyn (2010). "Introduction". Master Roger's Epistle to the Sorrowful Lament upon the Destruction of the Kingdom of Hungary by the Tatars. Central European University Press. pp. xli–liii. ISBN9789639776951. JSTOR10.7829/j.ctt2jbnhk.9. Carpegna Falconieri, Tommaso di (2005). "Giacomo di Palestrina". Enciclopedia Federiciana. Istituto dell'Enciclopedia Italiana.
Bak & Rady 2010, pp. xlii–xliii. Roger was back in James's service in 1236–1239, but he returned again to Hungary in time to experience Mongol invasion of 1241. He wrote an eyewitness account of the destruction in his Carmen miserabile. According to Carpegna Falconieri 2005, Tedaldo Visconti, the future Pope Gregory X, was another member of James's early legations. Bak, János M.; Rady, Martyn (2010). "Introduction". Master Roger's Epistle to the Sorrowful Lament upon the Destruction of the Kingdom of Hungary by the Tatars. Central European University Press. pp. xli–liii. ISBN9789639776951. JSTOR10.7829/j.ctt2jbnhk.9. Carpegna Falconieri, Tommaso di (2005). "Giacomo di Palestrina". Enciclopedia Federiciana. Istituto dell'Enciclopedia Italiana.
Carpegna Falconieri 2005; Wakefield 1974, pp. 149–150. Carpegna Falconieri, Tommaso di (2005). "Giacomo di Palestrina". Enciclopedia Federiciana. Istituto dell'Enciclopedia Italiana. Wakefield, Walter L. (1974). Heresy, Crusade, and Inquisition in Southern France, 1100–1250. University of California Press.