Ferromagnetism and superconductivity down to 0 K in b.c.t. ErRh 4B4 J.L. Genicon, A. Sulpice, R. Tournier, B. Chevalier and J. Etourneau J. Physique Lett., 44 17 (1983) 725-732 DOI: 10.1051/jphyslet:019830044017072500