1. N. A. Bergman, J. Am. Med. Assoc. 253, 675 (1935).
2. F. Boland, The First Anesthetic, p. 3ff, University of Georgia Press, Athens (1950).
3. C. W. Long, Southern Medical and Surgical Journal (New Series), 5 (1849).
4. C. Carlsson and S. Cooper, Anesth. Analg. 70, 339 (1990).
5. A. Dobkin, Development of New Volatile Inhalation Anesthetics, Vol. 6, p. 6, Excerpta Medica, New York, (1979).