Isoscalar dipole coherence at low energies and forbidden E1 strength P. Papakonstantinou, V.Yu. Ponomarev, R. Roth and J. Wambach Eur. Phys. J. A, 47 1 (2011) 14 Published online: 25 January 2011 DOI: 10.1140/epja/i2011-11014-7