pid type title authors mentors source_title published_date url doi isbn issn eissn efos:4231 "journal article" "Generation Z buying behavior change in the COVID-19 pandemic context" "Leko Šimić, M.; Pap, A." efos:4221 "journal article" "Students' Perceptions of Public vs. Private Higher Education Institution Brand Value in Croatia" "Ostojić, Martina; Leko Šimić, Mirna"