1. Alexander, P., Hudson, R.F., and Earland, C. "Wool, Its Chemistry and Physics," 2nd ed. Chapman & Hall, London, 1963, pp. 182, 213.
2. Action of Mixed Solvents on Wool
3. Blumenthal, W.B. "The Chemical Behavior of Zirconium," Van Nostrand , Princeton, N.J., 1958, p. 363.