Giacomo da Viterbo

James of Viterbo is the author of a collection of nearly 225 sermons, transmitted only by an autograph code.

James of Viterbo is considered the author of a Lectura in IV libros Sententiarum. Before the publication of Stegmüller's Repertorium Commentariorum in Sententias Petri Lombardi, the Lectura was believed to be transmitted only by the code G V 15 of the Biblioteca Comunale of Siena.

The Abbreviatio in I Sententiarum Aegidii Romani of James of Viterbo has long been regarded as a shortened form of the ordinatio of Giles of Rome’s Commentary on the first book of the Sententiae of Peter Lombard.