Konieczka, K
Bojinova, R I
Valmaggia, C
Schorderet, D F
Todorova, M G
Article History
Received: 16 December 2015
Accepted: 5 May 2016
First Online: 5 August 2016
Competing interests
: MGT and RIB have full access to all the data in the study and hold complete responsibility for the data integrity and the accuracy of the analysis. The authors declare no conflict of interest.