G. L. C.  Bramley, Forest, F., and de Kok, R. P. J., ?Troublesome tropical mints: re-examining generic limits of Vitex and relations (Lamiaceae) in South East Asia?, Taxon, vol. 58, pp. 500?510, 2009.

H. K.  Moon and Hong, S. P., ?Pollen morphology of the genus Lycopus (Lamiaceae)?, Annales Botanici Fennici, vol. 40, pp. 191?198, 2003.

H. - K.  Moon, Vinckier, S., Walker, J. B., Smets, E., and Huysmans, S., ?A search for phylogenetically informative pollen characters in the subtribe Salviinae (Mentheae : Lamiaceae)?, International Journal of Plant Sciences, vol. 169, pp. 455?471, 2008.

O.  Ryding, ?Revision of the Clinopodium abyssinicum group (Labiatae)?, Bot J Linn Soc, vol. 150, pp. 391?408, 2006.

H. - K.  Moon, Hong, S. - P., Smets, E., and Huysmans, S., ?Phylogenetic significance of leaf micromorphology and anatomy in the tribe Mentheae (Nepetoideae: Lamiaceae)?, Bot J Linn Soc, vol. 160, pp. 211?231, 2009.