To answer these questions, data was collected from the databases Web of Science and Chinal (EBSCOhost). The Google Scholar search engine was also used.
Til að fá svör við þessum spurningum var gagna leitað í gagna-söfnunum Web of Science, Chinal (EBSCOhost) auk þess sem fræðasetur www.google.com var notað.