M. W.  Frohlich, ?Systematics of Heliotropium section Orthostachys in Mexico?, Harvard University, Cambridge, Massachusetts, 1978.

G.  Brokamp, ?Die phylogenetische Analyse der Sektion Heliotropium L. sect. Cochranea (Miers) Kuntze?, Freie Universität Berlin, Berlin, 2006.

F.  Luebert, ?Systematics, ecology and evolution of Heliotropium sect. Cochranea and the biogeography of the Atacama Desert?, Freie Universität Berlin, Berlin, 2010.