Szkudlarz, Piotr, and Zbigniew Celka. “Morphological Characters of the Seed Coat in Selected Species of the Genus Hypericum L. And Their Taxonomic Value”. Biodiversity: Research and Conservation 44 (December 1, 2016): 1–9. Accessed January 5, 2026. https://pressto.amu.edu.pl/index.php/biorc/article/view/biorc-2016-0022.