MLPF: efficient machine-learned particle-flow reconstruction using graph neural networks Joosep Pata, Javier Duarte, Jean-Roch Vlimant, Maurizio Pierini and Maria Spiropulu Eur. Phys. J. C, 81 5 (2021) 381 Published online: 02 May 2021 DOI: 10.1140/epjc/s10052-021-09158-w