Eloff, J. “The Major Differences in Chemical Composition and Antibacterial Activity of Two Closely Related Leonotis Species (Lamiaceae) May Have Taxonomic Value”. Suid-Afrikaans Tydskrif Vir Natuurwetenskap En Tegnologie / <i>South African Journal of Science and Technology</I&gt;, Vol. 29, no. 1, Jan. 2010, pp. 30-38, doi:10.4102/satnt.v29i1.5.