Projection effects in galaxy cluster samples: insights from X-ray redshifts M. E. Ramos-Ceja, F. Pacaud, T. H. Reiprich, K. Migkas, L. Lovisari and G. Schellenberger A&A, 626 (2019) A48 Published online: 12 June 2019 DOI: 10.1051/0004-6361/201935111