Broadcasting" videos from the above presentation: Part 1: "Hanso Idzerda and his PCGG transmitter", Part 2: "Dutch Radio Pioneers Hanso Idzerda and Jan Corver", Part 3: "Hanso Idzerda's PCGG Radio Transmitter. How does it work?" (youtube.com) "The History of Dutch Broadcasting, part IV" by Joh. Schnabel, The Roman Catholic Radio Guide, third volume, number 81, July 16, 1927, pages 213 and 214 (English translation: www.r-type.org) Hanso Schotanus à Steringa Idzerda Biography of Idzerda. (huygens.knaw.nl, translated from Dutch) History of radio Defunct radio stations in the Netherlands Radio stations established in 1919 Radio stations disestablished in 1924