Dennis came to Penn as the library's first full-time Bibliographer for Middle Eastern Studies, a post which he held until he became Director for Collection Management and Development. He retired in 2002, but has continued to work part-time in several capacities since that time. One of his responsibilities is to develop the library's holdings in Russian, Eastern European and Slavic Studies. Dennis received his B.A. from the University of California (Riverside), his M.L.S. from Columbia University and his Ph.D. from Princeton University.