1 Correction to: Z. Angew. Math. Phys. (2021) 72:58 https://doi.org/10.1007/s00033-021-01480-3

In the original publication of the article, the first and last names of both the authors were swapped. The correct version of the author names is given below:

Claude Boutin . Francesco dell’Isola

The original article has been corrected.