Photos through decades
Check the full album
The 1974 Helsinki Convention was signed on 22 March 1974 by (from left) the Ministers of Denmark (Holger Hansen), Finland (Jermu Laine), German Democratic Republic (Hans Reichelt); the Secretary of State of the German Federal Republic (Hans-Georg Sachs); and the Ministers of Poland (Jerzy Kusiak), Sweden (Svante Lundkvist), and the Soviet Union (E. E. Alexchevsky).