EP672641-A  A.H. DIRKZWAGER ET AL. 'Sewage Sludge Treatment and Use: New Developments, Technological Aspects and Environmental Effects' 1988 , ELSEVIER APPLIED SCIENCE , LONDON, UK * page 502 *;  CHEMICAL ABSTRACTS, vol. 100, no. 17, 23 Avril 1984, Columbus, Ohio, US; abstract no. 138129p, I. PENTEK ET AL. 'Conversion of liquid manure and wastewaters into liquid fertilizer.' page 566 ; & HU-A-28 759 (VASIPARI KUTATO INTEZET ET AL.)EP672641-A1  A.H. DIRKZWAGER ET AL. "Sewage Sludge Treatment and Use: New Developments, Technological Aspects and Environmental Effects" 1988, ELSEVIER APPLIED SCIENCE, LONDON, UK;  A.H. DIRKZWAGER ET AL. &apos;Sewage Sludge Treatment and Use: New Developments, Technological Aspects and Environmental Effects&apos; 1988 , ELSEVIER APPLIED SCIENCE , LONDON, UK * page 502 *;  CHEMICAL ABSTRACTS, vol. 100, no. 17, 23 Avril 1984, Columbus, Ohio, US; abstract no. 138129p, I. PENTEK ET AL. &apos;Conversion of liquid manure and wastewaters into liquid fertilizer.&apos; page 566 ; &amp; HU-A-28 759 (VASIPARI KUTATO INTEZET ET AL.);  CHEMICAL ABSTRACTS, vol. 100, no. 17, 23041984, Columbus, Ohio, US; abstract no. 138129p, I. PENTEK ET AL. "Conversion of liquid manure and wastewaters into liquid fertilizer." page 566; & HU-A-28 759 (VASIPARI KUTATO INTEZET ET AL.)FR2717173-A1  A.H. DIRKZWAGER ET AL. "Sewage Sludge Treatment and Use: New Developments, Technological Aspects and Environmental Effects" 1990, ELSEVIER APPLIED SCIENCE, LONDON, UK page 502;  A.H. DIRKZWAGER ET AL. &apos;Sewage Sludge Treatment and Use: New Developments, Technological Aspects and Environmental Effects&apos; 1990 , ELSEVIER APPLIED SCIENCE , LONDON, UK * page 502 *;  CHEMICAL ABSTRACTS, vol. 100, no. 17, 23 Avril 1984, Columbus, Ohio, US; abstract no. 138129p, I. PENTEK ET AL. &apos;Conversion of liquid manure and wastewaters into liquid fertilizer.&apos; page 566 ; &amp; HU-A-28 759 (VASIPARI KUTATO INTEZET ET AL.);  CHEMICAL ABSTRACTS, vol. 100, no. 17, 23/04/1984, Columbus, Ohio, US; abstract no. 138129p, I. PENTEK ET AL. "Conversion of liquid manure and wastewaters into liquid fertilizer." page 566; & HU-A-28 759 (VASIPARI KUTATO INTEZET ET AL.)US5593473-A  A. H. Dirkzwager et al., "Sewage Sludge Treatment and Use: New ?Developments, Technological Aspects and Environmental Effects", Elsevier Applied Science, 1990, London, p. 502.;  I. Pentek et al., "Conversion of liquid manure and wastewaters into liquid fertilizer", Chemical Abstracts, vol. 100, No. 27, Apr. 23, 1984, Columbus, Ohio, p. 566.EP672641-B1  A.H. DIRKZWAGER ET AL. 'Sewage Sludge Treatment and Use: New Developments, Technological Aspects and Environmental Effects' 1988 , ELSEVIER APPLIED SCIENCE , LONDON, UK * page 502 *;  CHEMICAL ABSTRACTS, vol. 100, no. 17, 23 Avril 1984, Columbus, Ohio, US; abstract no. 138129p, I. PENTEK ET AL. 'Conversion of liquid manure and wastewaters into liquid fertilizer.' page 566 ; & HU-A-28 759 (VASIPARI KUTATO INTEZET ET AL.)