1. Richardson, P.M.: A Chemical Overview of the Labiatae. Advances in Labiatae Science Paper Abstracts, p. 1. Kew: Royal Botanic Gardens, 1991.
2. Martinez-Ripoll, M., J. Fayos, B. Rodriguez, M.C. Garcia-Alvarez, G. Savona, F. Piozzi, M. Paternostro, and J.R. Hanson: The Absolute Stereochemistry of Some Clerodane Diterpenoids from Teucrium Species. J.C.S. Perkin I, 1186–1190 (1981).
3. Merrit, A.T.L, and S.V. Ley: Clerodane Diterpenoids. Natural Product Reports 243–287 (1992).
4. Cantino, P.D.: A Phylogenetic Evaluation of Suprageneric Groups in the Labiatae, Among Others. Advances in Labiatae Science. Paper Abstracts, p. 4. Kew: Royal Botanic Gardens, 1991.
5. For revisions see Hanson, J.R.: In: Terpenoids and Steroids Specialist Periodical Reports, Vol. 12 and preceding volumes. London. The Chemical Society; and Nat. Prod. Reports 1–9 (1984–1992).