Varnava, Christiana
Stevenson, R Mark
Nilsson, Jonas
Skiba-Szymanska, Joanna
Dzurňák, Branislav
Lucamarini, Marco
Penty, Richard V
Farrer, Ian
Ritchie, David A http://orcid.org/0000-0002-9844-8350
Shields, Andrew J
Article History
Received: 5 October 2015
Revised: 21 January 2016
Accepted: 27 January 2016
First Online: 15 March 2016
Competing interests
: The authors declare no conflict of interest.