Funding for this research was provided by:
Horizon 2020 Research and Innovation programme (Marie Skłodowska-Curie Grant No. 675546)
Received: 26 April 2019
Accepted: 11 February 2020
First Online: 26 February 2020
Compliance with ethical standards
: FB is Managing Director of Dr. Brill + Partner GmbH. DMA was employed by Dr. Brill + Partner GmbH as part of a research network (European Union’s Horizon 2020 research and innovation programme, Marie Skłodowska-Curie Grant agreement No 675546) and declares no conflict of interest. DW declares no competing interests.