**Author details**

Joan Morales Alcúdia\* and Marina Romeo Delgado University of Barcelona (UB), Barcelona, Spain

\*Address all correspondence to: jmoralesal@uoc.edu

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
