AUTHOR=Jemielniak Dariusz TITLE=Researching Social Networks: Opportunities and Challenges JOURNAL=Frontiers in Human Dynamics VOLUME=2 YEAR=2020 URL=https://www.frontiersin.org/journals/human-dynamics/articles/10.3389/fhumd.2020.00001 DOI=10.3389/fhumd.2020.00001 ISSN=2673-2726