Funding for this research was provided by:
Spanish Ministry of Education (FPU14/06441)
Text and Data Mining valid from 2018-10-29
First Online: 29 October 2018
Compliance with Ethical Standards
: No funding was received specifically for the preparation of this review.
: Ana Isabel Fraguas-Sánchez was granted a research fellowship (FPU14/06441) from the Spanish Ministry of Education. Ana Isabel Fraguas-Sánchez and Ana Isabel Torres-Suárez have no conflicts of interest that are directly relevant to the contents of this article.