"Journal of Geophysical Research", 1967; vol.72(13): 3511-* Murphy CH, Bull GV: "Ionospheric winds over Yuma Arizona measured by gun-launched projectiles".
"Journal of Geophysical Research", 1967; vol.72(13): 3511-* Murphy CH, Bull GV: «Ionospheric winds over Yuma Arizona measured by gun-launched projectiles».