D.A.Webb (Boiss. & Heldr) 1987 - Chater AO (1987) Flora Europaea: Notulae systematicae ad Floram Europaeam spectantes Series 2 No. 1. Botanical Journal of the Linnean Society 95(4): 227-257. doi: 10.1111/j.1095-8339.1987.tb01857.x.