1. and Cellular Materials in Ency. Polym. Sci. Eng., 2nd Ed., 3, Wiley (1985).
2. and U.S. Patent 2,023,204 (1935).
3. (to Dow), U.S. Patent 2,515,250 (1950).
4. and (to Dow), U.S. Patent 3,067,147 (1962).
5. and (to DuPont), U.S. Patent 3,227,664 (1966).