Funding for this research was provided by:
Ministerio de Economía, Industria y Competitividad, Gobierno de España (TEC2015-68172-C2-1-P)
Text and Data Mining valid from 2019-06-17
Received: 18 January 2019
Accepted: 26 May 2019
First Online: 17 June 2019
: The authors declare that they have no competing interests.