Challenging the nature of low-energy plasmon excitations in CaC6 using electron energy-loss spectroscopyFriedrich Roth, Andreas König, Christian Kramberger, Thomas Pichler, Bernd Büchner and Martin KnupferEPL, 102 1 (2013) 17001DOI: https://doi.org/10.1209/0295-5075/102/17001