The WISSH quasars project - VI. Fraction and properties of BAL quasars in the hyper-luminosity regimeG. Bruni, E. Piconcelli, T. Misawa, L. Zappacosta, F. G. Saturni, G. Vietri, C. Vignali, A. Bongiorno, F. Duras, C. Feruglio, F. Tombesi and F. FioreA&A, 630 (2019) A111DOI: https://doi.org/10.1051/0004-6361/201834940
