Significant journals of science.

In 1974 the Science Citation Index (SCI) covered about 401,000 articles and communications in 2,443 scientific and technical journals. They cited about 3.2 million different publications an average of 1.8 times each. In this article some results of an analysis of more than 5 million citations in the references of journal articles indexed for the SCI in 1974 are presented and an attempt is made to interpret of those results in the light of an earlier study of 1969 citations.