• Thumbnail for United Kingdom patent 394325
    The United Kingdom patent 394325 'Improvements in and relating to Sound-transmission, Sound-recording and Sound-reproducing Systems' is a fundamental work...
    56 KB (6,334 words) - 07:41, 26 September 2024
  • Thumbnail for Sound recording and reproduction
    Music Online. Oxford University Press. Retrieved February 20, 2015. GB patent 394325, Alan Dower Blumlein, "Improvements in and relating to Sound-transmission...
    62 KB (7,778 words) - 02:03, 18 September 2024