Polarization measurement analysis - II. Best estimators of polarization fraction and angleL. Montier, S. Plaszczynski, F. Levrier, M. Tristram, D. Alina, I. Ristorcelli, J.-P. Bernard and V. GuilletA&A, 574 (2015) A136DOI: https://doi.org/10.1051/0004-6361/201424451