- ^ H. Schröder, C. Grundmann, J. Am. Chem. Soc. 78, 2447 (1956)
- ^ E. M. Smolin, L. Rapoport, The Chemistry of Heterocyclic Compounds, A. Weissberger, Ed., s-Triazines and Derivatives (Interscience, NY, 1959) p186
- ^ Merck Index 14th Ed.
- ^ A. Pinner, Chemische Berichte., 23, 2919 (1890)