Valkonen, Mira
Ruusuvuori, Pekka
Kartasalo, Kimmo
Nykter, Matti
Visakorpi, Tapio
Latonen, Leena
Article History
Received: 28 December 2016
Accepted: 13 February 2017
First Online: 20 March 2017
Competing interests
: The authors declare no competing financial interests.