Stelmach-Mardas, M
Iqbal, K
Mardas, M
Schwingshackl, L
Walkowiak, J
Tower, R J
Boeing, H
Article History
Received: 2 August 2016
Revised: 12 September 2016
Accepted: 14 October 2016
First Online: 30 November 2016
Competing interests
: The authors declare no conflict of interest.