Wachsmuth, P. ., Hambach, R. ., Kinyanjui, M. K., Guzzo, M. ., Benner, G. ., & Kaiser, U. . (2013). High-energy collective electronic excitations in free-standing single-layer graphene. Phys. Rev. B, 88, 075433. https://doi.org/10.1103/PhysRevB.88.075433 (Original work published 2024)