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).

Luebert, F., H. H.  Hilger, and M.  Weigend. 2011. ?Diversification in the Andes: Age and origins of South American Heliotropium lineages (Heliotropiaceae, Boraginales)?. Molecular Phylogenetics and Evolution 61(1):90 - 102. Retrieved  (http://dx.doi.org/10.1016/j.ympev.2011.06.001).