Khapugin, Anatoliy A. “Population Characteristics of Silaum Silaus (L.) Schinz & Thell. (Apiaceae) in Mordovia, a Highly Threatened Plant Species at the Northern Limit of Its Range”. Journal of Threatened Taxa 10, no. 1 (January 26, 2018): 11147–11155. Accessed September 18, 2021. https://threatenedtaxa.org/index.php/JoTT/article/view/3476.