Reference

J.-P. Zhu, Armin Guggisberg, M. Kalt-Hadamowsky, Michael Hesse (1990): Chemotaxonomic study of the genus Tabernaemontana (Apocynaceae) based on their indole alkaloid content – Österreichische Botanische Zeitschrift = Plant Systematics and Evolution – 172: 13 - 34.