1. M. V. Ardenne and D. Beischer, Angew. Chem. 53, 103 (1940).ANCEAD0044-8249
2. Gilman, Organic Syntheses (John Wiley & Sons. Inc., New York, 1932), p. 53.
3. P. Emmett, in Advances of Colloid Science (Interscience Publishing Corporation, New York, 1940) 1, 29.