Langen, Britta
Rudqvist, Nils
Spetz, Johan
Swanpalmer, John
Helou, Khalil
Forssell-Aronsson, Eva
Article History
Received: 6 November 2015
Accepted: 7 July 2016
First Online: 25 October 2016
Competing interests
: The authors declare no competing financial interests.