Khapugin, A. 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, vol. 10, no. 1, Jan. 2018, pp. 11147-55, doi:10.11609/jott.3476.10.1.11147-11155.