EFODON is the abbreviated title of Europäische Gesellschaft für frühgeschichtliche Technologie und Randgebiete der Wissenschaft eV, a German association dedicated to the study of world mysteries. It publishes a bi-monthly magazine Synesis, with much of the content of its earlier issues available online(a).
The content of the magazine is wide-ranging and inevitably deals with Atlantis as well as a number of other subjects included in Atlantipedia. Gernot L. Geise is on the committee of EFODON and contributes regularly to Synesis. You will also recognise that a number of the other contributors also feature in Atlantipedia.
It is clear that Synesis is sometimes used to promote the intellectual hobby-horses of some of the contributors, so keep your critical faculties at the ready.
(a) https://www.efodon.de/html/publik/sy/sy.html (German)
Gernot L. Geise (1945- ) & Reinhard Prahl (1967- ) Geise has written on a number of mysteries ancient and modern(b), the Pyramids, Revised Chronologies and three books on the alleged moon landing hoax(c).
As a guest author he offered a controversial paper on the Atlantisforschung.de website with the self-explanatory title of ‘The Giza pyramids were not built by ancient Egyptians’(d).
He has contributed regularly to the German EFODON magazine, of which he is a founding member.
Prahl has written on possible connections between the Guanches and the ancient Egyptians(a) and has collaborated with Geise to produce Auf der Suche nach der Mutterkultur (In Search of the Mother Culture)  in which they support the idea of Atlantis in the Antarctic.
(b) https://www.glgeise.de/ (German)