Menéndez, H
Ferrero, C
Martín-Hernández, J
Figueroa, A
Marín, P J
Herrero, A J
Article History
Received: 11 April 2015
Revised: 31 August 2015
Accepted: 12 September 2015
First Online: 13 October 2015
Competing interests
: The authors declare no conflict of interest.