Letter from Carvel Flood, secretary to Thomas Gold, to Dr Giovanni Silvestro, Instituto di Fisica Dell Universita, Torino, Italy Asking Dr Silvestro to send a paper which he and Gold wrote, 'Lens effect of the earth's ionosphere on radio waves reaching the moon' as they have mislaid it. Says that they have to send a corrected copy to 'Planetary and Space Science' before they will publish it. 22 February 1968