Originally Rapid Praha, then EFEKT Praha, then Crystalex, then the editorial board of Glasrevue on-line.
Jindrich Brok copyright:
For 70 years after his death, copyright rests with his family and heirs. Also copyright on many of Brok's images rests with UPM.
Simply because the journal has closed, Czechoslovakia and in particular Praha is within the now-Czech Republic, and Brok being dead, does not make the material free of copyright, or a free-for all for copyright piracy. The Czech Republic is a signatory of the Berne Convention.
For educational or non-commercional research the photographies can be used always.
This is not always the case.
Hence my use of this wording: "Image copyright CGR. Photographer Jindrich Brok. Used under copyright conditions of CGR".
This was a decision based on discussions with members of the Glasrevue editorial board.