WO2008141023-A1  DUAN X. ET AL.: 'Reduction processes of aromatic-bis(squarate)s' JOURNAL OF MOLECULAR STRUCTURE: THEOCHEM. vol. 529, no. 1-3, 08 September 2000, pages 161 - 171;  HASIOTIS C. ET AL.: 'Development and Characterization of Acid-Doped Polybenzimidazole/Sulfonated Polysulfone Blend Polymer Electrolytes for Fuel Cells' J. ELECTROCHEMICAL SOCIETY vol. 148, no. 5, 31 May 2001, pages A513 - A519;  JEONG J.K. ET AL.: 'A novel pi-conjugated polmer: poly(3,4-bis(phenylene)-3-cyclobutene-1,2-d ione)' POLYMER BULLETIN vol. 42, no. 2, 31 March 1999, pages 183 - 190;  JEONG J.K. ET AL.: 'A novel pi-conjugated polmer: poly(3,4-bis(phenylene)-3-cyclobutene-1,2-d ione)' POLYMER BULLETIN vol. 42, no. 2, 31 March 1999, pages 183 - 190, XP008126479;  HASIOTIS C. ET AL.: 'Development and Characterization of Acid-Doped Polybenzimidazole/Sulfonated Polysulfone Blend Polymer Electrolytes for Fuel Cells' J. ELECTROCHEMICAL SOCIETY vol. 148, no. 5, 31 May 2001, pages A513 - A519, XP008126480;  HASIOTIS C. ET AL.: 'Development and Characterization of Acid-Doped Polybenzimidazole/Sulfonated Polysulfone Blend Polymer Electrolytes for Fuel Cells' J. ELECTROCHEMICAL SOCIETY vol. 148, no. 5, 31 May 2001, pages A513 - A519, XP008130742;  See also references of EP 2158230A1EP2158230-A1  Andreas Schmidt: "Oxocarbonsaeuren" Roempp Online, Version 3.6 December 2006 (2006-12), XP002603946 Retrieved from the Internet: URL:http://www.roempp.com/prod/roempp.php [retrieved on 2010-10-05];  See also references of WO 2008141023A1US7879476-B2  Jeong, J.K. et al. "A novel ~p-conjugated polymer : poly (3,4-bis(phenylene)-3-cyclobutene-1,2-dione)", Polymer Bulletin, 42(2), pp. 183-190. Mar. 31, 1999.;  Duan, X. et al. "Reduction processes of aromatic-bis(squarate)s", Journal of Molecular Structure: THEOCHEM, 529(1-3), pp. 161-171. Sep. 8, 2000.;  Hasiotis, C. et al. "Development and Characterization of Acid-Doped Polybenzimidazole/Sulfonated Polysulfone Blend Polymer Electrolytes for Fuel Cells", J. Electrochemical Society, 148(5), pp. A513-A519. May 31, 2001.EP2158230-B1  Andreas Schmidt: "Oxocarbonsaeuren" Roempp Online, Version 3.6 December 2006 (2006-12), XP002603946 Retrieved from the Internet: URL:http://www.roempp.com/prod/roempp.php [retrieved on 2010-10-05];  JEONG J.K. ET AL.: 'A novel pi-conjugated polmer: poly(3,4-bis(phenylene)-3-cyclobutene-1,2-d ione)' POLYMER BULLETIN vol. 42, no. 2, 31 March 1999, pages 183 - 190, XP008126479;  DUAN X. ET AL.: 'Reduction processes of aromatic-bis(squarate)s' JOURNAL OF MOLECULAR STRUCTURE: THEOCHEM. vol. 529, no. 1-3, 08 September 2000, pages 161 - 171;  HASIOTIS C. ET AL.: 'Development and Characterization of Acid-Doped Polybenzimidazole/Sulfonated Polysulfone Blend Polymer Electrolytes for Fuel Cells' J. ELECTROCHEMICAL SOCIETY vol. 148, no. 5, 31 May 2001, pages A513 - A519, XP008130742