Reference
Lorenzo Peruzzi, Gabriella Aquaro, Giuliano Ceska (2004): Distribution, Karyology and Taxonomy of Onosma helvetica subspec. Lucana comb. nova. (Boraginaceae), a Schizoendemic in Basilicata and Calabria (S-Italy). – Phyton, Annales Rei Botanicae, Horn – 44_1: 69 - 81.