The e^+e^- → π^+ π^- π^+ π^-, K^+ K^- π^+ π^-, and K^+ K^- K^+ K^- cross sections at center-of-mass energies 0.5-GeV - 4.5-GeV measured with initial-state radiation - Aubert, Bernard; et al. (Phys. Rev. D, 2005)