I really still don't know enough about this.

It occurs to me to confess, I really still don't know where Pergamon actually is. The only reason I can type it is that my mother used to work at Pergamon Press, which was Robert Maxwell's academic publishing house in Oxford when I was a kid: the source (I believe) of his wealth, and the most poisonous place my mother ever worked.

I shall go to Wikipedia forthwith, and be marginally better informed...