Büchi, Felix N., Jean-François Affolter, Stefan Camenzind, Niels Chmielewski, Philipp Dietrich, Michael Höckel, Martin Ruge, and Marco Santis. 2004. “PEFC: Stacks, Systems, and Applications”. CHIMIA 58 (12):869. https://doi.org/10.2533/000942904777677074.