  In this report we examine the change in citation behavior since the
introduction of the arXiv e-print repository (Ginsparg, 2001). It has been
observed that papers that initially appear as arXiv e-prints get cited more
than papers that do not (Lawrence, 2001; Brody et al., 2004; Schwarz &
Kennicutt, 2004; Kurtz et al., 2005a, Metcalfe, 2005). Using the citation
statistics from the NASA-Smithsonian Astrophysics Data System (ADS; Kurtz et
al., 1993, 2000), we confirm the findings from other studies, we examine the
average citation rate to e-printed papers in the Astrophysical Journal, and we
show that for a number of major astronomy and physics journals the most
important papers are submitted to the arXiv e-print repository first.
