Monteoliva, M., A. Funes, E. García-Peregrín, M. F. Zafra, and M. Henares. “Biosynthesis of Terpenes in Pines”. Ars Pharmaceutica (Internet), vol. 10, no. 7-10, June 1969, pp. 285-47, https://revistaseug.ugr.es/index.php/ars/article/view/9671.