Mullard Magic: For All Your Vintage Valve and Radio Needs!
RSGB, AMATEUR RADIO HANDBOOK, 2ND EDITION , FROM 1941, ONE OF 5000
SERVICE VALVE EQUIVALENTS, RSGB, BOOK, 5TH EDITION, 1962
SERVICE VALVE EQUIVALENTS, RSGB, BOOK, 6TH EDITION, 1966
SERVICE VALVE EQUIVALENTS, RSGB, BOOK,3RD EDITION, 1948