R. Soc. Open Sci. 7, 190207. (Published 15 January 2020) (doi:10.1098/rsos.190207)
The below sentence has been added to the Introduction.
Preliminary work on the intermediacy was presented in [23].
Changes to the reference list
The following reference should, therefore, be added to the reference list.
23. Šubelj L, Waltman L, Traag V, van Eck NJ. 2019 Intermediacy of publications. In Proc. 17th Int. Conf. on Scientometrics & Informetrics ISSI ’19, Rome, Italy, 2 September, pp. 1288–1300. Leuven, Belgium: ISSI. See http://issi-society.org/publications/issi-conference-proceedings/proceedings-of-issi-2019.
The paper has now been updated.