Sorvari, Jouni. “Social Wasp (Hymenoptera: Vespidae) Beer Trapping in Finland 2008-2012: A German Surprise”. Entomologica Fennica 24, no. 3 (December 21, 2013): 156–164. Accessed December 22, 2024. https://journal.fi/entomolfennica/article/view/8983.