Grilli, Paolo, and Maria Balsamo. “LA COMUNITÀ MACROBENTONICA DELL’ALTO METAURO (APPENNINO UMBRO-MARCHIGIANO)”. Fragmenta Entomologica 41, no. 1 (October 31, 2009): 1-14. Accessed August 15, 2020. http://www.fragmentaentomol.org/index.php/fragmenta/article/view/80.