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

Weigend, M., M.  Gottschling, F.  Selvi, and H. H.  Hilger. 2010. ?Fossil and extant Western Hemisphere Boragineae, and the polyphyly of "Trigonotideae" Riedl (Boraginaceae: Boraginoideae)?. Systematic Botany 35(2):409 - 419. Retrieved  (http://www.bioone.org/doi/abs/10.1600/036364410X518874).

Weigend, M., M.  Gottschling, F.  Selvi, and H. H.  Hilger. 2009. ?Marbleseeds are gromwells - Systematics and evolution of Lithospermum and allies (Boraginaceae tribe Lithospermeae) based on molecular and morphological data?. Molecular Phylogenetics and Evolution 52(3):755 - 768. Retrieved  (http://www.sciencedirect.com/science/article/B6WNH-4WBK7BK-3/2/5ef424fa3684d5c985634011154460d5).

Weigend, M., F.  Luebert, F.  Selvi, G.  Brokamp, and H. H.  Hilger. 2013. ?Multiple origins for Hound?s tongues (Cynoglossum L.) and Navel seeds (Omphalodes Mill.) ? The phylogeny of the borage family (Boraginaceae s.str.)?. Molecular Phylogenetics and Evolution 68(3):604 - 618. Retrieved  (http://www.sciencedirect.com/science/article/pii/S1055790313001590).