Proximity to valence transition in heavy fermion superconductor CeCu2Si2 under pressure G. Seyfarth, A.-S. Rüetschi, K. Sengupta, A. Georges and D. Jaccard EPL, 98 1 (2012) 17012 Published online: 12 April 2012 DOI: 10.1209/0295-5075/98/17012