TY - BOOK TI - Annals of the international geophysical year U1 - REV/551.514/AIGY 21 PY - 1957/// CY - London PB - Pergamon Press KW - IONOSFERA KW - GEOFÍSICA N1 - Part I. Ionospheric vertical soundings -- Part II. The measurement of ionospheric absorption -- Part III. The measurement of ionospheric drifts -- Part IV. Miscellaneous radio measurements ER -