E.G.H.Oliv. & I.M.Oliv. 2005 - Oliver EGH, Oliver IM (2005) The genus Erica (Ericaceae) in southern Africa: taxonomic notes 2. Bothalia 35: 121-148. doi: 10.4102/abc.v35i2.388.
There is no corrections for Erica unicolor subsp. mutica yet.