1. Asbestos; Its Sources, Extraction, Preparation, Manufacture and Uses In Industry and Engineering, p. 15, Becker & Haag, Berlin (1928).
2. Personal involvements of the author in some cases, many media reports in others.
3. B. A. Andrews, Encyclopedia of Chemical Technology, Vol. 7 (M. Grayson, ed.), p. 193, Wiley, New York (1979).
4. Encyclopedia of Science and Technology, Vol. 5, p. 243, McGraw-Hill, New York (1960).
5. Anon., Chem. Eng. News
45, 30 (1967).