ATLAS Collaboration, Max Planck Institute for Physics, Max Planck Society and Cooperation Partners;
ATLAS Collaboration (2023). Observation of an excess of di-charmonium events in the four-muon final state with the ATLAS detector. Physical Review Letters, 131, 151902. Retrieved from https://publications.mppmu.mpg.de/?action=search&mpi=MPP-2023-81.