J. Linderski, review of Gary Forsythe, The Historian L. Calpurnius Piso Frugi and the Roman Annalistic Tradition
(Lanham: University Press of America, 1994), in American Journal of Philology
117 (1996) 329–332 (at 330), rpt. in Roman Questions II. Selected Papers
(Stuttgart: Franz Steiner Verlag, 2007), pp. 299-302 (at 300):
A commentary on a fragmentary work normally requires much more space than a commentary on a fully surviving author. In a surviving author the context for every piece of information is automatically provided; for fragments the historical and literary context of each piece has to be divined by a modern commentator.