Heywood (Talbot ex Benth.) 1972 - Heywood VH (1972) Flora Europaea: Notulae Systematicae ad Floram Europaeam spectantes: No. 13. Botanical Journal of the Linnean Society 65(4): 341-358. doi: 10.1111/j.1095-8339.1972.tb02277.x.
There is no corrections for Sideritis romana subsp. purpurea yet.