Didukh, Y., Chusova, O. and Demina, O. 2018. Syntaxonomy of chalk outcrop vegetation of the order Thymo cretacei-Hyssopetalia cretacei. Hacquetia. 17, 1 (Mar. 2018). DOI:https://doi.org/10.1515/hacq-2017-0013 .