Understanding multiply mentioned references

Although listed only once at the end of a scientific article, a reference can be mentioned repeatedly within the citing article. These references are defined as multiply mentioned references (MMRs). MMRs are universal in scientific writing. Using the references in Journal of Informetrics as an example, approximately 1/4 of the references are mentioned multiple times. The aim of this research was to provide a detailed understanding of MMRs, including their abundance within the citing paper, their locations and distributions, and their citation contexts in the first and subsequent mentions. The results show that longer articles are more likely to mention references multiply, and self-citing references are more likely to be mentioned multiple times. Normally, the multiple mentions of a reference tend to be located in the same section and quite close to each other. In terms of citation context, reference re-citations usually serve as supplementary explanations of their first-time mention within the citing paper. (C) 2017 Elsevier Ltd. All rights reserved.