I.K.Ferguson 1971 - Heywood VH (1971) Flora Europaea: Notulae Systematicae ad Floram Europaeam spectantes: No. 9. Botanical Journal of the Linnean Society 64(2): 199-235. doi: 10.1111/j.1095-8339.1971.tb02145.x.
There is no corrections for Verbascum levanticum yet.