1. I. S. Cooper, in: “Cryogenics in surgery” H. von Leden and W. G. Cahan eds., Medical Examination Publishing Company, Inc., Flushing, (1971), pp. 1–38 and p. 155.
2. R. Orpwood, Phys Med Biol 26: 555 (1981).
3. A. Gage and D. Torre, “Encyclopedia of Medical Devices and Instrumentation,” Wiley, New York (1988).
4. H. Lenz and J. Eichler, Cryobiology 13: 37 (1976).
5. T. E. Cooper and G. J. Petrovic, Journal of Heat Transfer 96: 415 (1974).