Selegej, V 1994Selegej, V, Sonwalkar, VS, Inan, US, Helliwell, RA, Chmyrev, VM, Sobolev, YP, Ovcharenko, OY Simultaneous observations of VLF ground transmitter signals on the DE 1 and COSMOS 1809 satellites: Detection of a magnetospheric caustic and a duct PDF (Online Viewing) 413.pdf