Volkova, Svetlana, Eugeniya Chavchavadze, and Mukhadi Umarov. 2012. “Ecological and Anatomical Analysis of the Secondary Xylem in Mountainous Xerophytic Plants of the Itum-Kala Arid Depression (Northern Caucasus)”. Biological Communications, no. 1 (March):3–9. https://biocomm.spbu.ru/article/view/4798.