Reconstructing solar magnetic fields from historical observations - III. Activity in one hemisphere is sufficient to cause polar field reversals in both hemispheresI. O. I. Virtanen, I. I. Virtanen, A. A. Pevtsov and K. MursulaA&A, 616 (2018) A134DOI: https://doi.org/10.1051/0004-6361/201732323
