A new state-observer of the inner PEM fuel cell pressures for enhanced system monitoring Olivier Bethoux, Emmanuel Godoy, Ivan Roche, Bruno Naccari, Miassa Amira Taleb, Mohamad Koteiche and Younane Nassif Eur. Phys. J. Appl. Phys., 66 3 (2014) 30901 Published online: 10 June 2014 DOI: 10.1051/epjap/2014130167