Jurgenson's second book from 1967 with the somewhat bombastic title "Sprechfunk mit Verstorbenen. Praktische Kontaktherstellung mit dem Jenseits." (Liter. translated: Speech-radio with Deceased. Practical Establishment of Contact with the Beyond.) A disastrous title which one for ever made it uninteresting for the serious public. But the book achieved several edition and is still obtainable today. It is an interesting and well written book and it is a pity that there never came an English edition - it would hade been not only a good supplement but also a needed contrast to Raudives "Breakthrough".
An apparently (deliberate?) overlooked important detail: In his book Jurgenson mentions eight instances where he recorded voices from persons who later turned out to be alive.

(Several similar cases: Bibliography 2a)