O.  Ryding, ?Pericarp structure and phylogeny of tribe Mentheae (Lamiaceae)?, Plant Syst Evol, vol. 285, pp. 165?175, 2010.

E.  J Oualidi, Verneau, O., Puech, S., and Dubuisson, J. Y., ?Utility of rDNA ITS sequences in the systematics of Teucrium section Polium (Lamiaceae)?, Plant Syst Evol, vol. 215, pp. 49?70, 1999.