| Contracting Parties | Signature | Ratification (Instrument deposited on) |
Entry into force |
| GERMANY | 10.09.1964 | 25.06.1969 | 25.07.1969 |
| BELGIUM | 10.09.1964 | / | / |
| FRANCE | 10.09.1964 | / | / |
| GREECE | 10.09.1964 | 22.01.1987 | 21.02.1987 |
| NETHERLANDS | 10.09.1964 | 10.02.1967 | 29.05.1968 |
| TURKEY | 10.09.1964 | 29.04.1968 | 29.05.1968 |
| + SPAIN | 10.09.1964 | 16.12.1976 | 15.01.1977 |
| + accession |