On the nature of grain boundaries in the colossal magnetoresistance manganites J. Klein, C. Höfener, S. Uhlenbruck, L. Alff, B. Büchner and R. Gross Europhys. Lett., 47 3 (1999) 371-377 Published online: 01 September 2002 DOI: 10.1209/epl/i1999-00398-1