1. 1) Leonard J.Goldwater, John H.Harley., William B.Warris., Joseph J.Fitzgerald., Milton S.Dunn: Dangerous Properties of Industrial Materials, p. 319, 320, New York (1957)
2. 2) Ernst W.Baader: Gewerbekrankheiten, p. 58 (1931)
3. 3) Rubner-Gruber., Ficker: Handbuch der Hygiene, IV 2, p. 178 (1919)
4. 4) Rubner-Gruber., Ficker: Handbuch der Hygiene, IV 2, p. 178 (1919)
5. 5) V.Oettingen: Arch. f. exp. Pathol. u. Pharmak., 80 (1916)