About the Authors

Nees Jan van Eck

ecknjpvan@cwts.leidenuniv.nl

Affiliation Centre for Science and Technology Studies, Leiden University, Leiden, The Netherlands

Ludo Waltman

Affiliation Centre for Science and Technology Studies, Leiden University, Leiden, The Netherlands

Anthony F. J. van Raan

Affiliation Centre for Science and Technology Studies, Leiden University, Leiden, The Netherlands

Robert J. M. Klautz

Affiliation Department of Cardiothoracic Surgery, Leiden University Medical Center, Leiden, The Netherlands

Wilco C. Peul

Affiliation Department of Neurosurgery, Leiden University Medical Center, Leiden, The Netherlands

Competing Interests

Nees Jan van Eck, Ludo Waltman, and Anthony F. J. van Raan are affiliated with the Centre for Science and Technology Studies of Leiden University, which has commercial interests in the production of bibliometric indicators. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: NJE LW. Performed the experiments: NJE LW. Analyzed the data: AFJR RJMK WCP. Contributed reagents/materials/analysis tools: NJE LW. Wrote the paper: NJE LW AFJR RJMK WCP.