Kummu, Matti http://orcid.org/0000-0001-5096-0163
Taka, Maija
Guillaume, Joseph H. A. http://orcid.org/0000-0001-6854-8708
Article History
Received: 16 May 2017
Accepted: 8 December 2017
First Online: 6 February 2018
Competing interests
: The authors declare no competing financial interests.