• PrefaceJajuga, Krzysztof; Locarek-Junge, Hermann; Orłowski, Lucjan T.; Staehr, KarstenContemporary Trends and Challenges in Finance : proceedings from the 4th Wroclaw International Conference in Finance2019 / p. v-vii https://link.springer.com/content/pdf/bfm%3A978-3-030-15581-0%2F1.pdf https://www.scopus.com/sourceid/21101077468 https://www.scopus.com/record/display.uri?eid=2-s2.0-85125636266&origin=inward&txGid=ff07d083de88dc0d4a362f52b81bd87e