ZAJĄC, Maria; ZAJĄC, Adam. Directional northern element in the flora of vascular plants of Poland. Biodiversity: Research and Conservation, [S. l.], v. 21, p. 19–26, 2011. DOI: 10.2478/v10119-011-0004-z. Disponível em: https://pressto.amu.edu.pl/index.php/biorc/article/view/v10119-011-0004-z. Acesso em: 19 jan. 2026.