1. 1974.Chemical and Engineering News12 , May 6,p.
2. Struth, B. 1974. 3–6. ,Reprint of Papers, Division of Chemical Marketing and Economics, American Chemical Society 168th Meeting, Atlantic City, New Jersey, September 10–12,pp.
3. Ericsson, R. L.Ibid.17–28. ,pp.
4. DeWitt, J. D.Ibid.37–45. ,pp.