A homologous series Pb2n+1Nb2n−1O7n−1 studied by electron microscopyCh. Leroux, T. Badeche, G. Nihoul, O. Richard and G. van TendelooEur. Phys. J. AP, 7 1 (1999) 33-40DOI: https://doi.org/10.1051/epjap:1999196