See Franjo Rački: Ocjena starijih izvora za hrvatsku i srbsku poviest srednjega vieka" Književnik I (1864) 358 – 388. [1] and Stéphane Gioanni, The bishops of Salona (2nd–7th century) in the Historia Salonitana by Thomas the Archdeacon (13th century) : history and hagiography, in Écrire l’histoire des évêques et des papes, Fr. Bougard and M. Sot (edd.), Brepols, 2009, pp. 243–263
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James Ross Sweeney: "Thomas of Spalato and the Mongols: a Thirteenth-Century Dalmatian Views of Mongol Customs." Florilegium 4 (1982): 156 – 183. https://doi.org/10.3138/flor.4.010