Valchovski, Hristo Ivailov. “Checklist of Earthworms (Oligochaeta: Lumbricidae) from Bulgaria—a Review”. Zootaxa 3458, no. 1 (September 7, 2012): 86–102. Accessed April 18, 2025. https://mapress.com/zt/article/view/zootaxa.3458.1.4.