1. BfArM (Bundesinstitut für Arzneimittel und Medizinprodukte), 1995, Abwehr von Arzneimittelrisiken— L-Tryptophan-haltige Arzneimittel, Berlin, Bescheid vom 13:12.
2. Brown, R.R., Fisrtte, P.L., Arend, R.A., and Ozaki, Y., 1994, Altered tryptophan metabolism and immune parameters in eosinophilia-myalgia syndrome, in: L-Tryptophan: Current Prospects in Medicine and Drug Safety. W. Kochen and H. Steinhart, eds.pp. 255–262, de Gruyter, Berlen.
3. Dabre, T., Nussbaumer, C., and Borschberg, H.-J., 1984, Synthesis of (-)-horbatine and related indole alkaloids, Helv. Chem. Acta, 67:1038–1051.
4. Goda, Y., Suzuki, J., Maitani, T., Yoshihira, K., Takeda, M., and Uchiyama, M., 1992, 3-Anilino-L-alanine, structural determination of UV-5, a contaminant in EMS-associated L-tryptophan samples, Chem. Pharm. Bull., 40:2236–2238.
5. Gray, R.A., 1959, Preparation and properties of 3-indoleacetaldehyde, Arch. Biochem. Biophys., 81:480–488.