Highly sensitive search for magnetic fields in white dwarfs using broad-band circular polarimetryAndrei V. Berdyugin, Vilppu Piirola, Stefano Bagnulo, John D. Landstreet and Svetlana V. BerdyuginaA&A, 657 (2022) A105DOI: https://doi.org/10.1051/0004-6361/202142173