Halford, AJ 2004Spasojevic, M, Engebretson, MJ, Posch, JL, Halford, AJ, Shelburne, GA, Smith, AJ, Inan, US, Arnoldy, RL Latitudinal and seasonal variations of quasiperiodic and periodic VLF emissions in the outer magnetosphere PDF (Online Viewing) 2004-03.pdf