Why could electron spin resonance be observed in a heavy fermion Kondo lattice? B. I. Kochelaev, S. I. Belov, A. M. Skvortsova, A. S. Kutuzov, J. Sichelschmidt, J. Wykhoff, C. Geibel and F. Steglich Eur. Phys. J. B, 72 4 (2009) 485-489 Published online: 10 November 2009 DOI: 10.1140/epjb/e2009-00386-9