Funding for this research was provided by:
Vicerrectoría de Investigación, Universidad de Costa Rica (723-B7-219)
Kompetenzzentrum frühe Bildung in Stendal
Text and Data Mining valid from 2019-03-27
Accepted: 19 March 2019
First Online: 27 March 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: The study reported here was approved by the appropriate ethics committee at the Universidad de Costa Rica and at the University of Applied Sciences Magdeburg-Stendal. The study was performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. All persons gave their informed consent prior to their inclusion in the study.