Martin Ryle AutographPrinted scientific leaflet signed, six pages (on three conjoined sheets), 6 x 10,5 inch, scientific leaflet `Mullard Radio Astronomy Observatory` (from Cavendish Laboratory Cambridge), signed and inscribed on the first page in blue ballpoint ink "To Franz Wilkus Greetings! Martin Ryle", with a horizontal fold and mild signs of wear in fine to very fine condition.