P.W.Ball (Polatschek) 1990 - Chater AO (1990) Flora Europaea: Notulae systematicae ad Floram Europaeam spectantes. Series 2. No. 3. Botanical Journal of the Linnean Society 103(3): 197-220. doi: 10.1111/j.1095-8339.1990.tb00184.x.
There is no corrections for Erysimum pusillum subsp. cephalonicum yet.