Statistics from Altmetric.com
Contributors MS and DOK conceived of the concept. NJ and ZG reviewed the existing literature and analysed the data presented. All four authors contributed to final version of the manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; internally peer reviewed.
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