1. N. J. Delollis, in “Handbook of Adhesives”, edited by I. Skeist (Reinhold, New York London, 1962) p. 512.
2. R. J. Schliekelmann in “Adhesion and adhesives”, vol. 2, edited by R. Houwink and G. Salomon (Elsevier London, New York, 1967) Ch. 15.
3. H. S. Katz and J. V. Milewski, “Handbook of Fillers and Reinforcements for Plastics” (Van Nostrand Reinhold, New York, 1978) p. 3.
4. C. S. Jr Hurlbut, “Dana's Manual of Mineralogy”, 18th Edn (Wiley, New York, 1971).
5. I. Skeist, “Epoxy Resins” (Reinhold, New York, 1958) p. 77.