VISINONI, L., PERNOLLET, C. A. , DESMET J.-F., KORNER-NIEVERGELT, f. & JENNI, l. (2015) – zootier-lexikon.org https://www.zootier-lexikon.org/index.php?option=com_k2&view=item&id=4889%3Avisinoni-l-pernollet-c-a-desmet-j-f-korner-nievergelt-f-jenni-l-2015&Itemid=217
Alpine Rock Ptarmigan (Lagopus muta helvetica) during summer
Alpine Rock Ptarmigan (Lagopus muta helvetica) during summer