I presume you mean an edition of a certain date?
I haven't been for a long time, but the central library in Geneva had a reading room on the top floor, with backdates of various major newspapers / magazines, and a photocopier. You could ask at the reception on the ground floor.
If they don't have that now, they may be able to suggest where else to look.
Otherwise, I would suggest maybe in one of the UN libraries.. no idea which one though..