  In this paper we show that the dramatic increase in the number of research
articles indexed in the Web of Science database impacts the commonly observed
distributions of citations within these articles. First, we document that the
growing number of physics articles in recent years is due to existing journals
publishing more and more papers rather than more new journals coming into being
as it happens in computer science. And second, even though the references from
the more recent papers generally cover a longer time span, the newer papers are
cited more frequently than the older ones if the uneven paper growth is not
corrected for. Nevertheless, despite this change in the distribution of
citations, the citation behavior of scientists does not seem to have changed.
