Information were gathered in databases from Chinal, EBSCOhost and PubMed, Google Scholar (http://scholar.google.com), Gegnir.is and Skemman.
Heimilda var aflað frá gagnagrunnunum Chinal, EBSCOhost og PubMed, fræðasetri google (scholar.google.com), Gegnir.is og Skemmunni.