Comparison of results on Neff from various Planck likelihoods S. Henrot-Versillé, F. Couchot, X. Garrido, H. Imada, T. Louis, M. Tristram and S. Vanneste A&A, 623 (2019) A9 Published online: 25 February 2019 DOI: 10.1051/0004-6361/201834060