Characterization of a subsample of the Planck SZ source cluster catalogues using optical SDSS DR12 dataA. Streblyanska, R. Barrena, J. A. Rubiño-Martín, R. F. J. van der Burg, N. Aghanim, A. Aguado-Barahona, A. Ferragamo and H. LietzenA&A, 617 (2018) A71DOI: https://doi.org/10.1051/0004-6361/201732306