WO9304013-A  CHEMICAL ABSTRACTS, vol. 112, no. 24, 11 June 1990, Columbus, Ohio, US; abstract no. 222200k, K.NITTA 'Manufacture of high-purity porous ceramics' page 332 ;;  CHEMICAL ABSTRACTS, vol. 112, no. 24, 11 June 1990, Columbus, Ohio, US; abstract no. 222204q, F.ISO 'Manufacture of porous ceramics' page 332 ;;  CHEMICAL ABSTRACTS, vol. 113, no. 26, 24 December 1990, Columbus, Ohio, US; abstract no. 236558r, K. FUTAKI ET AL. 'Manufacture of porous alumina ceramics' page 312 ;;  CHEMICAL ABSTRACTS, vol. 114, no. 6, 11 February 1991, Columbus, Ohio, US; abstract no. 48323g, H. YORITA ET AL. 'Manufacture of high-alumina porous ceramics, and the ceramics obtained' page 333 ;;  PATENT ABSTRACTS OF JAPAN vol. 13, no. 84 (C-572)(3432) 27 February 1989 & JP,A,63 270 368 ( OKURA IND CO LTD ) 8 November 1988EP598783-A  See references of WOA 9304013WO9304013-A1  CHEMICAL ABSTRACTS, vol. 112, no. 24, 11 June 1990, Columbus, Ohio, US; abstract no. 222204q, F.ISO &apos;Manufacture of porous ceramics&apos; page 332;  CHEMICAL ABSTRACTS, vol. 113, no. 26, 24 December 1990, Columbus, Ohio, US; abstract no. 236558r, K. FUTAKI ET AL. &apos;Manufacture of porous alumina ceramics&apos; page 312;  CHEMICAL ABSTRACTS, vol. 112, no. 24, 11 June 1990, Columbus, Ohio, US; abstract no. 222200k, K.NITTA &apos;Manufacture of high-purity porous ceramics&apos; page 332;  CHEMICAL ABSTRACTS, vol. 114, no. 6, 11 February 1991, Columbus, Ohio, US; abstract no. 48323g, H. YORITA ET AL. &apos;Manufacture of high-alumina porous ceramics, and the ceramics obtained&apos; page 333;  PATENT ABSTRACTS OF JAPAN vol. 13, no. 84 (C-572)(3432) 27 February 1989 &amp; JP,A,63 270 368 ( OKURA IND CO LTD ) 8 November 1988;  See also references of EP 0598783A1EP598783-A1  See references of WO 9304013A1EP598783-B1  CHEMICAL ABSTRACTS, vol. 112, no. 24, 11/06/1990, Columbus, Ohio, US; abstract no. 222200k, K.NITTA "Manufacture of high-purity porous ceramics" page 332; & JP-A-01252589;  CHEMICAL ABSTRACTS, vol. 112, no. 24, 11/06/1990, Columbus, Ohio, US; abstract no. 222204q, F.ISO "Manufacture of porous ceramics" page 332; & JP-A-01242474;  CHEMICAL ABSTRACTS, vol. 113, no. 26, 24/12/1990, Columbus, Ohio, US; abstract no. 236558r, K. FUTAKI ET AL. "Manufacture of porous alumina ceramics" page 312 & JP-A-02229713;  CHEMICAL ABSTRACTS, vol. 114, no. 6, 11/02/1991, Columbus, Ohio, US; abstract no. 48323g, H. YORITA ET AL. "Manufacture of high-alumina porous ceramics, and the ceramics obtained" page 333; & JP-A-02149482;  PATENT ABSTRACTS OF JAPAN vol. 13, no. 84 (C-572)(3432) 27/02/1989 & JP-A-53270368