Approximate NLO parton distribution functions with theoretical uncertainties: MSHT20aNLO PDFs J. McGowan, T. Cridge, L. A. Harland-Lang and R. S. Thorne Eur. Phys. J. C, 83 3 (2023) 185 Published online: 01 March 2023 DOI: 10.1140/epjc/s10052-023-11236-0