Source: Valdés, B. & Raab-Straube, E. von (2011+): Boraginaceae. – In: Euro+Med Plantbase - the information resource for Euro-Mediterranean plant diversity.
A.Bacchetta, G., Coppi, A., Pontecorvo, C. & Selvi, F. 2008: Systematics, phylogenetic relationships and conservation on the taxa of Anchusa (Boraginaceae) endemic to Sardinia (Italy). – Syst. Biodivers. 6: 161-174