Sandecki, Rafał. 2016. “The Sedge Carex Secalina – Critically Endangered Species in Poland: New Locality in the Breeding Colony of Black-Headed Gull Chroicocephalus Ridibundus”. Biodiversity: Research and Conservation 42 (November):27-31. https://doi.org/10.1515/biorc-2016-0011.