Funding for this research was provided by:
Secretary for Universities and Research of the Ministry of Economy and Knowledge of the Government of Catalonia (GENCAT 2015 DI 050)
Text and Data Mining valid from 2019-04-10
Received: 11 January 2019
Accepted: 19 March 2019
First Online: 10 April 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.