Riesgo, A
Pérez-Portela, R
Pita, L
Blasco, G
Erwin, P M
López-Legentil, S
Article History
Received: 19 October 2015
Revised: 8 April 2016
Accepted: 25 April 2016
First Online: 7 September 2016
Competing interests
: The authors declare no conflict of interest.