Wrzalik, M. (2018). The results of parliamentary and presidential elections and referendums worldwide from April 1 -September 30, 2018: https://doi.org/10.26485/SW/2018/26/7. Studia Wyborcze, 26, 125-140. https://journals.ltn.lodz.pl/Studia-Wyborcze/article/view/226 (Original work published 2021)