| 1969 | Members (16): Austria, Belgium, Bulgaria, Canada, Czechoslovakia, Denmark, Finland, Germany (BRD and DDR), Hungary, Japan, Norway, Poland, Sweden, Switzerland, UK |
| 1969 | Members (16): Austria, Belgium, Bulgaria, Canada, Czechoslovakia, Denmark, Finland, Germany (BRD and DDR), Hungary, Japan, Norway, Poland, Sweden, Switzerland, UK |