Fermi surface studies on the organic superconductor κ(BEDT-TTF)2Cu(N(CN)2)Br [kappa-(BEDT-TTF)-2-Cu-(N-(CN)-2)-Br] and on the alkaline earth subnitride NaBa3N by means of magneto-quantum oscillationsHerbert Dieter WeißÉpuisé4,3Prévenez-moi