sentences:  De Rossi devoted himself to three chief lines of investigation—-typographical, bibliographical, and text-critical.Influenced by the example of Benjamin Kennicott, he determined on the collection of the variant readings of the Old Testament, and for that purpose collected a large number of manuscripts and old editions.In order to determine their bibliographical position he undertook a critical study of the annals of Hebrew typography, beginning with a special preliminary disquisition in 1776, and dealing with the presses of Ferrara (Parma, 1780), Sabbionetta (Erlangen, 1783), and, later, Cremona (Parma, 1808), as preparatory to his two great works, "Annales Hebræo-Typographici" (Parma, 1795, sec.