Nuclear uncertainties in the determination of proton PDFs - NNPDF Collaboration Richard D. Ball, Emanuele R. Nocera and Rosalyn L. Pearson Eur. Phys. J. C, 79 3 (2019) 282 Published online: 27 March 2019 DOI: 10.1140/epjc/s10052-019-6793-5