Vírseda-Chamorro, M
Salinas-Casado, J
Rubio-Hidalgo, E
Gutiérrez-Martín, P
Esteban-Fuertes, M
Article History
Received: 22 December 2014
Revised: 19 April 2015
Accepted: 8 May 2015
First Online: 30 June 2015
Competing interests
: The authors declare no conflict of interest.