Hilger, H. H. et al. 2005. ?The {Euro+Med} treatment of Boraginaceae in Willdenowia 34 - a response?. Willdenowia 35:43?48.

Selvi, F., A.  Papini, H. H.  Hilger, M.  Bigazzi, and E.  Nardi. 2004. ?The phylogenetic relationships of Cynoglottis (Boraginaceae-Boragineae) inferred from {ITS}, {5.8S} and {trnL} sequences?. 246:195?209.

Selvi, F., M.  Bigazzi, H. H.  Hilger, and A.  Papini. 2006. ?Molecular phylogeny, morphology and taxonomic re-circumscription of the generic complex {Nonea/Elizaldia/Pulmonaria/Paraskevia} (Boraginaceae-Boragineae)?. 55:907?918.

Hilger, H. H., F.  Selvi, A.  Papini, and M.  Bigazzi. 2004. ?Molecular systematics of Boraginaceae tribe Boragineae based on {ITS1} and {trnL} sequences, with special reference to Anchusa s.l.?. 94:201?212.