Appleton, Edward.
The Application of Ionospheric Data to Radio Communication / Appleton Edward, Beynon W.J.G.. - London : H.M.S.O., 1948. - 44 s.; 24 cm.
The Application of Ionospheric Data to Radio Communication / Appleton Edward, Beynon W.J.G.. - London : H.M.S.O., 1948. - 44 s.; 24 cm.