National Party of Europe (sources?)

[Komi]

https://en.wikipedia.org/wiki/National_Party_of_Europe

Anyone know if there was much documentation published by this group back in the day? Or if there have been any academic studies of them as an organisation? So far I haven't turned up much other than some passing references to the 1962 Venice Declaration in books about the postwar far-right. Maybe as a starting point, does anyone know where to find the full, original text of the Venice Declaration? That could be a useful primary source.