Niskanen, Johannes
Sahle, Christoph J.
Ruotsalainen, Kari O.
Müller, Harald
Kavčič, Matjaž
Žitnik, Matjaž
Bučar, Klemen
Petric, Marko
Hakala, Mikko
Huotari, Simo
Article History
Received: 28 August 2015
Accepted: 14 January 2016
First Online: 18 February 2016
Competing interests
: The authors declare no competing financial interests.