1. F. P. Bundy, H. T. Hall, H. M. Strong, R. H. Wentorf, Nature 176, 81 (1955)
2. M. W. Geis and J. C. Angus, Scientific American, October 1992 p.64
3. H. Hora, Chemische Rundschau (Basel) 14, 393 (1961)
4. H. Hora, Japanese Patent 472771 ( 16 July 1965 )
5. Brit. Patent 1,0011,308 (11 Aug. 1965);