Funding for this research was provided by:
Ministerio de Educación, Cultura y Deporte (FPU16/05358)
Ministerio de Economía, Industria y Competitividad, Gobierno de España (EDU2011-27840)
Received: 17 August 2018
Accepted: 12 March 2019
First Online: 16 March 2019
Compliance with ethical standards
: Authors declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants included in the study.