Côté, Benoit, Eichler, Marius, Arcones, Almudena, Hansen, Camilla J., Simonetti, Paolo, Frebel, Anna, Fryer, Chris L., Pignatari, Marco, Reichert, Moritz, Belczynski, Krzysztof, Matteucci, Francesca, "Neutron star mergers might not be the only source of r-process elements in the Milky Way", The Astrophysical Journal, 2019