Funding for this research was provided by:
Universidad Nacional de Educacion Distancia
Article History
Accepted: 15 February 2022
First Online: 25 February 2022
Declarations
:
: The manuscript does not contain clinical studies or patient data. All procedures performed in studies involving human participants were in accordance with the ethical standards of the Universidad Nacional de Educación a Distancia (UNED) and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from the parents of all individual participants.
: The authors declare that they have no conflict of interest.