PrefaceJajuga, Krzysztof; Locarek-Junge, Hermann; Orlowski, Lucjan T.; Staehr, KarstenContemporary trends and challenges in finance : proceedings from the 5th WroclawInternational Conference in Finance2020 / p. v-vi https://link.springer.com/content/pdf/bfm:978-3-030-43078-8/1?pdf=chapter%20toc Conference proceeding at Scopus Article at Scopus